Process for the production of cyclic sulfonium salts

ABSTRACT

A process for the production of a 5-7 membered ring cyclic sulfonium salt compound, including a 5-7 membered ring cyclic sulfonium salt compound having a non-nucleophilic anion, is described. Members of the latter group are potentially useful as initiators for cationic polymerizations. The process comprises reacting a 1.4-, 1.5-, or 1.6-diol compound or a 5-7 membered ring cyclic ether compound with a mercapto compound and a strong protonic acid yielding the cyclic sulfonium salt compound. Some compounds described are also novel compounds per se.

This application is a continuation of application Ser. No. 08/084,192,filed Jul. 2, 1993, abandoned and which is a 371 of PCT/SE91/00749 Nov.6, 1991, published as WO93/09112 May 13, 1993.

The present invention relates to a process for the production of a 5-7membered ring cyclic sulfonium salt compound, including a 5-7 memberedring cyclic sulfonium salt compound having a non-nucleophilic anion.Representatives of the latter group are potentially useful as initiatorsfor cationic polymerizations. More specifically, the invention relatesto a process comprising reacting a 1,4-, 1.5-, or 1,6-diol compound or a5-7 membered ring cyclic ether compound with a mercapto compound and astrong protonic acid yielding the cyclic sulfonium salt compound.

The process of the invention is general, efficient, and performable inone step resulting in a product in high yield and purity, and a widevariety of 5-7 membered ring cyclic sulfonium salt compounds can beproduced by the invention. The invention further relates to somecompounds which are novel compounds per se. These novel compounds wereproduced by the process of the invention.

BACKGROUND OF THE INVENTION

Tris organo sulfonium salts is an important class of sulfur compounds.Sulfonium salts have received renewed interest since the discovery thatsome triaryl sulfonium salts could be utilized as latent initiators forcationic polymerization, as disclosed in U.S. Pat. Nos. 4,058,400 and4,058,401. These salts were activated photochemically. More recently, ithas been found that some benzylic sulfonium salts can be utilized aslatent thermal initiators for cationic polymerization, see for examplePCT-application SE 90/00179 (23 Mars 1989); U.S. Pat. No. 5,013,814 (16Jan. 1989); Japan-patent no. JP 63,221,111 (11 Mars 1987) Chem. Abstr.1989, 111, 40092; Endo. T and Uno, H. J. Polym. Sci., Polym. Lett. Ed.1985, 23,359; Pappas S. P. and Hill. L. W. J. Coat. Technol. 1981, 53,43.

The latter have been shown to be thermally labile and decompose uponheating, leading to heterolytic cleavage of a sulfur-carbon bondyielding a sulfide and a carbocation capable of initiating the cationicpolymerization. It has also been shown that the propagation rate of thecationic polymerization is very much dependent of the nature of theanion and as a result it is necessary that the sulfonium salt initiatorhas a non-nucleophilic anion X⁻, e.g. SbF₆ ⁻, PF₆ ⁻, AsF₆ ⁻, and BF₄ ⁻,as disclosed in U.S. Pat. Nos. 4,058,400 and 4,058,401. J. Appl. PolymerSci. 1978, 43, 4826 and Makromol. Chem. 1985. 136.

PRIOR ART

Methods for producing sulfonium salts have been extensively reviewed,see for example, Methoden der Organischen Chemie (Houben-Weyl) 1955,Volume IX, 171 ff, and 1985, supplement E 11,405 ff; Lowe, P. A. TheChemistry of the Sulphonium Group, Ed. Stirling and Patai 1981, 267-313.More specifically, synthetic routes for preparing cyclic sulfonium saltshave also been described, see for example Dittmer, D. C. and Patwardhan,B. H. The Chemistry of the Sulphonium Group Ed. Stirling and Patai,1981, 387-522. Some of the methods most frequently used includemonoalkylation of a sulfide or dialkylation of a mercaptan with apowerful alkylating agent R-Y, such as an alkyl halide, whereby theleaving group of the alkyl halide becomes the counter ion of thesulfonium cation. However, these methods are suffer from a number ofdisadvantages;

Firstly, there are limitations in alkylating agents which are reactiveenough to succeed in alkylating a sulfide. Therefore, in the most cases,the structural scope of R is limited to methyl, primary alkyl, orbenzylic groups. Among the alkyl halides, alkyl iodides are normallyrequired and only in favorable cases bromides can be used.

Secondly, due to the limited access of alkylating agent consisting ofany of the anions above as the nucleofuge. Meerwein's salt (triethyloxonium tetrafluoroborate; Et₃ O⁺ BF₄ ⁻) is an exception, anion-exchanging step is required in order to prepare a cyclic or acyclicsulfonium salt having a non-nucleophilic anion, leading to additionalprocess steps. The ion-exchange is achieved by addition of a salt A⁺ X⁻(A is usually an alkali metal or silver) and from the mixture thedesired cyclic or acyclic sulfonium salt has to be isolated. Theefficiency of such a metathesis step relies on complete and selectiveextraction of the desired R₃ S⁺ X⁻ to a suitable organic solvent orfinding a solvent system wherein R₃ S⁺ Y⁻ is soluble and R₃ S⁺ X⁻precipitates. The conditions of a complete metathesis would more or lessdepend on the substrate since structural changes very often affectssolubility properties and the conditions have to be optimized in eachcase. The use of a silver salt as a precipitating agent for removal ofthe halide is another drawback for economical reasons, see equation 1.##STR1##

A much more attractive method for making a sulfonium salt having anon-nuclephilic anion is the acid-promoted alkylation of sulfur withalcohols or ethers whereby the anion of the strong acid becomes thecounter-ion of the sulfonium ion. Methods for producing sulfonium saltshaving non-nucleophilic anions by alkylation of sulfides with alcoholsor ethers promoted by protonic acids are previously known, such as thosedescribed in: Fichter, Sjostedt Chem. Ber. 1910, 43, 3422; HinsbergChem. Ber. 1929, 62, 127 and 1936, 69, 492; Milligan, Minor J. Org.Chem. 1963, 28, 235; Bosshard Helv. Chim. Acta 1970, 53, 1271; JuliaTetrahedron Lett. 1979, 1101; Okuma et al, Heterocycles 1987,26, 2343;PCT-application SE 90/00179 (23 Mars 1989); U.S. Pat. No. 5,013,814 (16Jan. 1989).

However, a general, convenient, and efficient method has not yet beendeveloped starting from simple mercaptans. Syntheses of some cyclicsulfonium salts made by an intra-molecular alkylation of a mercaptanpromoted by acid have been reported--Eastman. R. H. and Kritchevsky, G.J. Org. Chem. 1959, 24, 1428. However, in these examples, verycomplicated mercaptans were used, which had to be synthesized prior tothe cyclization. These examples lack generality.

PCT-application SE 90/00179 describes some cyclic sulfonium salts havingnon-nucleophilic anions used as latent thermal initiators forcationically polymerizable compounds. It was shown that the thermalstability of 2-aryl tetrahydrothiophenium sulfonium salts could becontrolled by the the aryl group. All salts were synthesized by knownmethods utilizing strong electrophiles such as alkyl halides andMeerwein's salt for alkylation of cyclic sulfides. These methods sufferfrom the drawbacks mentioned above. Such salts can now be produced muchmore efficiently and in higher yields and purity using the process ofthe present invention. In addition, the present invention allows thesynthesis of a wide variety of different 2-aryl tetrahydrothiopheniumsulfonium salts allowing fine tuning of the initiator properties such asinitiating temperature, solubility and "shelf life".

SUMMARY OF THE INVENTION

The present invention provides a novel and efficient process for theproduction of a 5-7 membered ring cyclic sulfonium salt compound,including a 5-7 membered ring cyclic sulfonium salt compound having anon-nucleophilic anion. Members of the latter group are potentiallyuseful as initiators for cationic polymerizations. More specifically,the process comprises reacting a 1,4-, 1,5-, or 1,6-diol compound or a5-7 membered ring cyclic ether compound with a mercapto compound and astrong protonic acid yielding the cyclic sulfonium salt compound havingthe desired anion.

The invention also provides a general process for the production of awide variety of structurally different cyclic sulfonium salt compounds.The structural plurality available by this invention includes thesulfur-containing heterocyclic ring, which is derived from the diol orthe cyclic ether reactant, the "R"-substituent which is derived from themercaptan reactant, and X⁻ which is derived from the acid reactant.These three reactants can be varied independently allowing production ofa large number of possible 5-7 membered ring cyclic sulfonium salts. Inaddition, by using either a di- or polyfunctional mercapto compound or adi- or polyfunctional diol or cyclic ether compound as the reactant itis possible to produce a di- or polyfunctional sulfonium salt, i.e. acompound containing two or more cyclic sulfonium groups.

The invention provides mild reaction conditions and room temperature orslightly above is generally applicable. The process is very efficientand substantially equimolar amounts (relative to the functional groups)of the diol/cyclic ether compound and the mercapto compound with aslight excess of the protonic acid is sufficient to form the sulfoniumsalt compound quantitively. Since the sulfonium salt compound is formedquantitatively (in most cases) the workup simply includes removal ofexcess protonic acid reactant followed by recrystallization of the crudeproduct, thus making the process very easily adaptable for large scaleproduction.

It is well known to those skilled in the an that many diols and cyclicethers are generally easily accessible, both as commercially availablestarting materials and also by the numerous organic transformationsavailable for the production of diols and ethers. The invention allowssynthesis of a wide variety of 5 to 7 membered cyclic sulfonium salts bysimply varying the diol or ether reactant.

The mercapto compound, according to this invention, can be selected froma wide variety of structurally different mercaptans such as methylmercaptan, primary, secondary, tertiary alkyl mercaptans, arylmercaptans, dimercaptans, and polymercapto compounds, consisting of bothstraight, cyclic and branched chain hydrocarbyl groups.

According to this invention, any strong protonic acid can furnish thetransformation of the diol/cyclic ether compound and the mercaptocompound to the sulfonium salt compound. This implies that by selectingthe protonic acid, structurally different sulfonium salt compoundshaving a wide variety of anions, i.e. anions of desired properties, canbe produced, including sulfonium salt compounds having non-nucleophilicanions.

The possibilities of producing pure and structurally different cyclicsulfonium salts having different anions are thereby markedly improvedsince the process does not introduce any other anions, than thecorresponding base to the strong acid, that otherwise could contaminatethe desired sulfonium salt.

The structural scope of the alkylating agent according to the prior an,i.e. where a cyclic sulfide is alkylated intermolecularly, is inpractice limited to methyl and primary alkyl halides. Synthesis ofcyclic sulfonium salts having a secondary or tertiary hydrocarbyl groupattached to the sulfur atom by alkylation of a sulfide with a secondaryor a tertiary alkyl halide are not possible. There are no suchlimitations in the present invention, wherein the diol or the cyclicether group, promoted by the strong protonic acid, alkylates themercapto group. The cyclic sulfonium salts having the structuresdiscussed above can easily be produced in high yields and purity. Asnoted above, the mercaptan can be selected from methyl mercaptan,primary, secondary, or tertiary alkyl, or aryl mercaptans.

According to the process of the invention, either a diol or thecorresponding cyclic ether can be used as one of the reactants. The diolor the corresponding cyclic ether can be mono-, di- or polyfunctional.At an early stage of the reaction under the conditions of the invention,i.e. the presence of a strong protonic acid, the diol is firsttransformed to the corresponding cyclic ether, see FIG. 1. Suchtransformations are well known from the literature, see for exampleSchmoyer et al, Nature 1960, 187, 592, where 1,4-butanediol wastransformed to tetrahydrofuran. However, under the specific conditionsof the present invention, i.e. in the presence of a mercaptan and astrong protonic acid, the reaction proceeds directly to the sulfoniumsalt product via the intermediate cyclic ether product and anintermediate sulfidoalcohol. Consequently, there is an equivalencebetween a diol and the corresponding cyclic ether and either of themcould be used as one of the reactants, see equation 2. ##STR2## Theinvention very efficiently utilizes the reactants since the wastedleaving group is one or two water molecule/s (18 or 36 grams per mole offormed sulfonium salt) when using a cyclic ether or a diol as thealkylating agent, as compared to the prior art where in the first stepiodide (129 grams per mol of sulfonium salt) is wasted when utilizing analkyl iodide as the alkylating agent. In order to obtain the desirednon-nucleophilic anion, the necessary ion-exchange leads to anadditional waste, usually an alkali metal such as sodium or potassium,or silver; 23, 39, and 108 atomic units, respectively. In summary, thetwo-step procedure: an alkyl iodide followed by sodiumhexafluorophosphate would produce a waste of 152 g of sodium iodide,whereas the one-step diol route produces 32 g of waste per mole ofsulfonium salt which in the latter case is water. Consequently, more ofthe reactants ends up in the sulfonium salt by employing the presentinvention.

Other objectives and advantages will become apparent from the detaileddescription of the invention which follows.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a process for the production of a 5-7membered ring cyclic sulfonium salt compound comprising reacting a 1,4-,1,5-, or 1,6-diol compound or a 5-7 membered ring cyclic ether compoundwith a mercapto compound and a strong protonic acid.

The reaction is performed by adding the strong protonic acid to themercapto compound and the resulting mixture is added to the diol orcyclic ether compound, or the strong protonic acid is added to a mixturecontaining the mercapto compound and the diol or cyclic ether compound,in substantially equimolar amounts with respect to the functional groupsinvolved.

The reaction is thus performed in the above preferred order of mixing ofthe reactants. Reverse order of mixing, i.e. first mixing the strongprotonic acid with the diol/cyclic ether compound in the absence of themercapto compound, usually results in unwanted and rapid polymerizationof the diol/cyclic ether compound.

According to this invention the mercapto compound can be mono-, di-, orpolyfunctional, with respect to the mercapto group. The diol or cyclicether compound can be mono-, di-, or polyfunctional, with respect to thediol or cyclic ether group. Polyfunctionality relates to three or moregroups, preferably 3-50 groups for the diol or cyclic ether compound andpreferably 3-500 groups for the mercapto compound.

The present invention also relates to the process above for theproduction of a cyclic sulfonium salt compound having a non-nucleophilicanion. Typically, a non-nucleophilic anion is characterized by apolyatomic molecule, MZ_(n) ⁻ consisting of a central atom Msymmetrically surrounded by 4 or 6 atoms Z which are moreelectronegative than the central atom. A non-nucleophilic anion havenone or very little ability to form covalent bonds and usually they arethe corresponding base to a very strong protonic acid.

According to one embodiment of the invention the process comprisesreacting: (a) a mercapto compound having the formula R¹ --SH, wherein R¹in a monofunctional mercaptan represents methyl, primary, secondary, ortertiary alkyl or cycloalkyl; aryl, preferably phenyl, which isunsubstituted or mono- or independently polysubstituted by alkyl,cycloalkyl, alkoxy, thioalkoxy, phenyl, phenoxy or thiophenoxy; andnaphthyl; arylalkyl, preferably benzyl, which is unsubstituted or mono-or independently polysubstituted by alkyl, alkoxy or thioalkoxy; or R¹in a di- or a polyfunctional mercaptan represents --[A-SH]_(m), whereinm≧1, and A independently represents alkylene, preferably C₂ -C₂₀,arylene, preferably phenylene, biphenylene or naphthylene;alkylenebisaryl preferably methylenebiphenyl; or aralkylene, preferablyxylylene, with

(b) a diol compound selected from the group consisting of formula I:##STR3## wherein n is 1,2, or 3,

R² independently represents hydrogen, alkyl, cycloalkyl, or aryl,preferably ##STR4## wherein y is an integer between 0 and 5, and R⁷independently represents alkyl, alkoxy, thioalkoxy, halogen, cyano,alkyl sulfonyl, aryl sulfonyl, preferably phenyl sulfonyl, aryl,aryloxy, or thioaryloxy, wherein the aryl group preferably is phenylwhich is unsubstituted or mono- or independently polysubstituted byalkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy, thiophenoxy,cyano, alkyl sulfonyl, or aryl sulfonyl, preferably phenyl sulfonyl,

R³ independently represents hydrogen, alkyl, cycloalkyl, aryl,preferably phenyl, which is unsubstituted or mono- or independentlypolysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen,phenoxy or thiophenoxy,

R⁴ independently represents hydrogen, alkyl, cycloalkyl, aryl,preferably phenyl, which is unsubstituted or mono- or independentlypolysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen,phenoxy or thiophenoxy, or R³ and R⁴ together form an aryl group fusedwith the corresponding carbon atoms of the carbon-carbon backbone chain,preferably ##STR5## wherein z is an integer between 0 and 4, and R⁸independently represents alkyl, alkoxy, thioalkoxy, halogen or phenyl,

R⁵ independently represents hydrogen, alkyl, cycloalkyl, aryl,preferably phenyl, which is unsubstituted or mono- or independentlypolysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen,phenoxy or thiophenoxy,

R⁶ independently represents hydrogen, alkyl, cycloalkyl, aryl,preferably phenyl, which is unsubstituted or mono- or independentlypolysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen,phenoxy or thiophenoxy, or

(c) a cyclic ether compound selected from the group consisting offormula II: ##STR6## wherein n, R², R³, R⁴, R⁵, and R⁶ are as definedabove,

(d) and a strong protonic acid having the formula HX, wherein Xrepresents a halogen or a group of the formula MY_(r), wherein Mrepresents Sb, P, B, As, or Cl; Y represents a halogen or oxygen; and ris an integer between 4 and 6, or X represents a group RSO₃ wherein R isOH alkyl, aryl or halogen substituted alkyl or aryl group, yielding amonofunctional cyclic sulfonium salt compound, when R¹ ≠--[A-SH]_(m),having the following structural formula III-1: ##STR7## wherein n, R¹,R², R³, R⁴, R⁵, R⁶, and X are as defined above with the exception ofthat R¹ ≠--[A-SH]_(m) ; or a di- or polyfunctional cyclic sulfonium saltcompound, when R¹ =--[A-SH]_(m), having the following structural formulaIII-2: ##STR8## wherein n, m, A, R², R³, R⁴, R⁵, R⁶ , and X are asdefined above.

The reaction of the process involves displacement of the oxygen atom/sby the sulfur atom, yielding the cyclic sulfonium salt compound havingthe structural formulae above. The invention also comprises arearrangement reaction, under the conditions of the process as definedabove; When the diol compound of formula I) or the cyclic ether compoundof II), when n=1 and R³ and R⁴ together form a fused aryl group asdefined, one R² can additionally define an 1-alkenyl, (R⁹)₂ C═C(R¹⁰)--,wherein R⁹ and R¹⁰ independently represent hydrogen, alkyl, cycloalkyl,aryl, preferably phenyl, or a 5-7 membered ring formed by R⁹ and R¹⁰ ;preferably hydrogen, i.e. a vinyl group, yielding a cyclic sulfoniumsalt compound having the following structural formula IV: ##STR9##wherein R¹, R², R⁵, R⁶, R⁸, and z are as defined, exept that R¹≠--[A-SH]_(m).

Mercapto compounds which are useful in this reaction can be selectedfrom mono-, di- or polyfunctional mercaptans. Suitable monofunctionalmercaptans can be selected from methyl mercaptan, primary, secondary, ortertiary alkyl or cycloalkyl mercaptans, in which the term "alkyl"includes both straight and branched chain saturated hydrocarbyl moietiesand generally includes moieties having from 2 to 20 C-atoms, includingethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl,n-pentyl, iso-pentyl, sec-pentyl, neo-pentyl, n-hexyl, iso-hexyl,n-heptyl, iso-heptyl, octyl, nonyl, decyl, undecyl, dodecyl, hexadecyl,and octadecyl moieties, preferably the moieties having 1 to 12 C-atoms,and the term "cycloalkyl" includes cyclic saturated hydrocarbyl moietiesand generally includes moieties having from 3 to 7 C-atoms in the cyclicmoiety, preferably 5 to 7, such as cyclopentyl, cyclohexyl, andcyclopheptyl in which the cyclic moiety can be directly bonded to themercapto group or separated from the mercapto group by an alkylenegroup, such as methylene. Further monofunctional mercaptans which areuseful in this reaction can be selected from aryl mercaptans, preferablyphenyl mercaptans, which are unsubstituted or mono- or independentlypolysubstituted by alkyl, preferably C₁ -C₈, cycloalkyl, preferably C₅-C₇, alkoxy, preferably C₁ -C₈, thioalkoxy, phenyl, phenoxy, orthiophenoxy, or naphtyl mercaptan; arylalkyl mercaptans, preferablybenzyl mercaptans, which are unsubstituted or mono- or independentlypolysubstituted by alkyl, alkoxy, or thioalkoxy. Preferredmonofunctional mercaptans in the reaction are primary, secondary, andtertiary alkyl, aryl, and benzyl mercaptans, most preferably theprimary, secondary, and tertiary C₂ -C₁₂ alkyl mercaptans.

Suitable di- and polyfunctional mercaptans in this reaction can beselected from compounds of the general formula HS--[A-SH]_(m), whereinm≧1, and A independently represents alkylene which can be substituted,preferably C₂ -C₂₀, for example ethylene, propylene, butylene,pentylene, hexylene; arylene, preferably phenylene, biphenylene ornaphthylene; alkylenebisaryl, preferably metylenebifenyl; or aralkylene,preferably xylylene. Examples of dimercaptans are: 1,2-ethane-dithiol,1,3-propane-dithiol, 1,4-butane-dithiol, 2,3-butane-dithiol,1,6-hexane-dithiol, and α,α'-dimercapto-p-xylene. Polymercaptans canconsist of an oligomeric or polymeric chain having pendant mercaptogroups.

Diol or cyclic ether compounds which are useful in this reaction can beselected from mono-, di- or polyfunctional diols or cyclic ethers.Suitable monofunctional diols and cyclic ethers can be selected from1,4-, 1,5-, 1,6-diols, or 5-7 membered ring cyclic ether compounds (i.e.tetrahydrofurans, tetrahydropyrans, or hexahydrooxepins) respectively,which are i) unsubstituted, or ii) mono- or independentlypolysubstituted by alkyl, preferably C₁ -C₈, cycloalkyl, preferably C₅-C₇, 1-alkenyl, preferably vinyl, aryl preferably phenyl, which isunsubstituted or mono- or independently polysubstituted by alkyl,preferably C₁ -C₁₂, cycloalkyl, preferably C₅ -C₇, alkoxy, preferably C₁-Cl₂, thioalkoxy, preferably C₁ -C₄, halogen, cyano, alkyl sulfonyl,preferably C₁ -C₆, aryl sulfonyl, preferably phenyl sulfonyl, aryl,preferably phenyl, aryloxy, preferably phenoxy, or thioaryloxy,preferably thiophenoxy; and/or iii) aryl fused, preferably benzo, whichis unsubstituted or mono- or independently polysubstituted by alkyl,preferably C₁ -C₁₂, cycloalkyl, preferably C₅ -C₇, alkoxy, preferably C₁-C₁₂, thioalkoxy, preferably C₁ -C₄, halogen, preferably chloro andbromo, phenyl, phenoxy, or thiophenoxy, or iv) cycloalkyl fused, whichis unsubstituted or mono- or independently polysubstituted by alkyl,preferably C₁ -C₈,

The preferred non-fused 1,4-, 1,5-, and 1,6-diols and 5-7 membered ringcyclic ether compounds, respectively, are i) unsubstituted, or ii) mono-or independently polysubstituted by alkyl, preferably C₁ -C₈, aryl,preferably phenyl, which is unsubstituted or mono- or independentlypolysubstituted by alkyl, preferably C₁ -Cl₂, cycloalkyl, preferably C₅-C₇, alkoxy, preferably C₁ -C₁₂, thioalkoxy, preferably C₁ -C₄, halogen,preferably chloro and bromo, phenyl, phenoxy or thiophenoxy. The mostpreferred 1,4-, 1,5-, and 1,6-diols and 5-7 membered ring cyclic ethercompounds, respectively, are aryl substituted.

When having substitution by one or more aryl groups, one arylsubstituent is preferably at the 1-position of the 1,4-, 1,5-, and1,6-diol and in the 2-position of the 5 -7 membered ring cyclic ether.The substituents on this aryl group preferably consist of anycombination of alkyl or alkoxy including both straight and branchedchain saturated hydrocarbyl moieties, preferably C₁ -C₁₂, morepreferably C₁ -C₈, most preferably C₁ -C₄. When the aryl group is phenylwhich is i) monosubstituted, the substitution is preferably in the4-position, or ii) polysubstituted, the substitution is preferably inany combinations of the 2-, 4-, or 6-positions. Examples of such phenylsubstituents are 4-alkyl-, 2,4-dialkyl-, 2,4,6-trialkyl-, 4-alkoxy-,2,4-dialkoxy-, 2,4,6-trialkoxy-, 2-alkyl-4-alkoxy-, 2-alkoxy-4-alkyl-,2,6-dialkoxy-4-alkyl-, and 2,6-dialkyl-4-alkoxy-substituents.

The diols discussed above are preferably selected from the 1,4-diols,and the cyclic ethers are preferably selected from the tetrahydrofurans.

The preferred fused 1,4-, 1,5-, and 1,6-diols, or 5-7 membered ringcyclic ethers, respectively, are i) unsubstituted, or ii) mono- orindependently polysubstituted by alkyl, preferably C₁ -C₈, cycloalkyl,preferably C₅ -C₇, vinyl, preferably in the 1-position, aryl, preferablyphenyl, and iii) (2,3)-aryl fused, preferably (2,3)-benzo for the diols,or (3,4)-aryl fused, preferably (3,4)-benzo for the cyclic ethers.

Suitable di- and polyfunctional diols and cyclic ethers in this reactioncan be selected from compounds of the general formula C-[B-C]_(w),wherein w≧1, C independently represents the 1,4-, 1,5-, and 1,6-diols,tetrahydrofurans, tetrahydropyrans, or hexahydrooxepions, respectively,defined as above, and B independently represents alkylene which can besubstituated, preferably C₂ -C₂₀, for example ethylene, propylene,butylene, pentylene, hexylene; arylene, preferably phenylene,biphenylene or naphthylene; alkylenebisaryl, preferably metylenebifenyl;or aralkylene, preferably xylylene. The C to B attachment is preferablyvia the 1-position of the diol or via the 2-position of the cyclicether.

Strong protonic acids which arc useful in this reaction can in principlebe selected from any strong protonic acid. A strong acid (HX) isrecognized by more or less complete dissociation in an aqueous solutionto form a proton (H⁺) and the corresponding base (X⁻). Suitable strongprotonic acids can be selected from: hydrohalogenic acids, such ashydrochloric, hydrobromic, and hydroiodic acid; perhalogenic acids, suchas perchloric acid; tetrahaloboric acids, such as tetrachloroboric andtetrafluoroboric acid; hexahaloantimonic, -arsenic, and -phosphoricacids, such as hexachloroantimonic, hexafluoroantimonic,hexachloroarsenic, hexafluoroarsenic, hexachlorophosphoric, andhexafluorophosphoric acid; sulfonic and halogen-substituted alkyl oraryl sulfonic acids, such as p-toluensulfonic andtriflic(trifluoromethane sulfonic)acid; phosphoric acid or sulfuricacid. Preferred strong protonic acids are perchloric, tetrafluoroboric,hexafluoroantimonic, hexafluoroarsenic, hexafluorophosphoric acid,p-toluensulfonic and triflic acid, most preferably tetrafluoroboric,hexafluoroantimonic, and hexafluorophosphoric acid.

In the production of a cyclic sulfonium salt compound having anon-nucleophilic anion, the strong protonic acid is preferably selectedfrom tetrafluoroboric, hexafluoroantimonic, hexafluoroarsenic, orhexafluorophosphoric acid, most preferably hexafluoroantimonic orhexafluorophosphoric acid.

Since the corresponding base of the acid becomes the anion of thesulfonium salt compound, an ion-exchanging step is not necessary whenusing these preferred acids for producing a sulfonium salt compoundhaving a non-nucleophilic anion. This results in a simplified one-stepprocess.

When using commercial hexafluorophosphoric acid, stabilized by about 10%w/w of hydrogen fluoride, the reaction is preferably performed in areaction vessel which not consists of glass, but preferably a vesselconsisting of plastic materials or monel alloy, most preferably apolyolefinic materials such as polyethylene, polypropylene, or teflon.

The reaction can be carried out in an anhydrous protonic acid or ahydrous protonic acid solution. The term "protonic acid" refers to thestrong protonic acids defined above. Preferably and conveniently thecommercially available protonic acid solution is used, the concentrationof which is dependent on the actual protonic acid. Examples of aqueousprotonic acids are hexafluorophosphoric acid commercially available as60% w/w solution, and hexafluoroantimonic acid available as the hydrate.HSbF₆.6H₂ O. If desired, the anhydrous protonic acid, the hydrousprotonic acid or the hydrous protonic acid solution can also be dilutedwith water to any convenient concentration, dependent on the actualprotonic acid. More concentrated protonic acid solutions are howeverpreferred since lower concentration will result in decreased overallreaction rate of the process. The concentration of aqueous protonic acidreactant is preferably at least 25%, more preferably at least 40%, ormost preferably at least 50% w/w.

The reaction can be carried out in the presence or absence of an inertorganic solvent. The presence of an inert organic solvent usually butnot necessary leads to a two-phase system. Examples of such inertsolvents are hydrocarbons, such as n-pentane, n-hexane, n-heptane,cyclohexane; aliphatic nitriles such as acetonitrile; dimethylsulfoxide; and halogenated hydrocarbons, such as carbon tetrachloride,methylene chloride, chloroform, tetrachloro ethane, dichloro ethane, andethylene dichloride. Of these, halogenated hydrocarbons, particularlymethylene chloride, are preferred.

When an inert solvent is present in the reaction, the amount of thesolvent can be varied depending on the type of solvent, the type andamount of the mercapto compound, strong protonic acid, and thediol/cyclic ether compound, etc. The amount of the solvent is preferablysmall since if the amount is too large, the overall reaction ratedecreases. A preferred amount of solvent is less than about 2000,suitable about 200 ml per mole of the diol/cyclic ether compound.

The amount of the strong protonic acid the reaction is at least 0.5equivalents (eq), more preferably at least 1.0 eq, most preferably atleast 1.2 eq. and at most 10 eq, preferably at most 5 eq, mostpreferably at most 2 eq, based on the diol/cyclic ether compound. Theamount of the mercapto compound in this reaction is at least 0.5 eq,preferably at least 0.9 eq, most preferably at least 1.0 eq, and at most10 eq, preferably at most 5 eq, most preferably at most 2 eq, based onthe diol/cyclic ether compound. The reaction can be carried out withequimolar amounts of the diol/cyclic ether compound and the mercaptocompound with a slight excess of the protonic acid reactant. Therelevant stochiometry of the reactants discussed herein refers to thereacting functional groups. Concequently, total conversion of, forexample, 1 mole of a difunctional mercaptan (2 eq--SH) theoreticallyrequires 2 moles of a monofunctional diol/cyclic ether and 2 moles of aprotonic acid. The excess of acid required depends on the reactivity ofthe acid and the diol/cyclic ether compound. In some cases, an excess ofthe acid of 0.2 equivalents can be sufficient to carry the reaction tocompletion. However, use of larger excess of acid leads to higherreaction rate with almost no additional workup problems.

Since the diol/cyclic ether compound in most cases is the most expensiveof the reactants, it is economically desirable to achieve highconversion of the diol/cyclic ether compound into the cyclic sufoniumsalt compound. This implies that the diol/cyclic ether compound shouldbe the limiting component. It is, however, possible to reduce the amountof the mercapto compound to 1 equivalent relative to the diol/cyclicether compound and still produce the sulfonium salt compound in highyield and purity. This is of great importance and value since minimizingthe excess of the mercapto compound will, in addition to improvedeconomy, decrease the bad smell, caused by unreacted mercapto compound,from the effluents from the workup. It is also possible to perform thereaction with less than 1 eq, for example 0.95 eq, of the mercaptocompound, resulting in total conversion of the mercapto compound intothe sulfonium salt compound, thus almost eliminating any mercaptan smellfrom the workup.

The reaction is preferably performed at a temperature from about 0° toabout 70° C., more preferably from about 20° to about 50° C.,particularily at room temperature. Higher reaction temperature may beuseful in some cases due to sluggish reactants. Mixing the reactantsrequire cooling due to exothermic ring-opening of the cyclic ether whichis either added as a reactant or formed in situ from the correspondingdiol. The temperature of the coolant should in some cases be subzero,lower than -10° C., more preferably lower or equal to 0° C. mostpreferably lower than 10° C. The reaction can be performed at pressuresranging from sub-atmospheric pressure to super-atmospheric pressure,preferably at atmospheric pressure. Superatmospheric pressure may becaused by volatile or gaseous reactants such methylmercaptan orhydrochloric acid. The reaction can be performed under an airatmosphere. When long reaction times arc needed, the atmosphericoxidation of the mercaptan to a disulfide may be a problem. Theoxidation can simply be avoided by performing the reaction under aninert gas atmosphere, preferably nitrogen or argon.

Some cyclic sulfonium salts of the invention are novel compounds per se.They all have benzylic substituents with respect to the sulfur atom,i.e. all are 2-aryl substituted. Such compounds are useful as latentthermal initiators for cationic polymerization, wherein the thermallatency primarily depends on the ability of the aryl substituent tostabilize positive charge at a benzylic position. The invention providesa tool for producing sulfonium salt initiators with improved solubilityin polymerizable compounds which often are caracterized of hydrophobicand non-polar properties. The increased hydrophobicity was achieved byusing long chain hydrocarbyl mercaptans, exemplified among the novelcompounds per se. The flexibility of the reaction allows this finetuning which constitutes a important technical contribution sincesolubility is problem associated with previously developed sulfoniumsalt initiators. Also, by the process of the invention, these novelcompounds are produced in higher purity compared to previously knowncompounds of this type, leading to a more well-defined product and moreuniform initiating characteristics.

The compounds which are novel per se are aryl-substituted or aryl-fusedcyclic sulfonium salt compounds having the structural formula V, VI, andVII which are: ##STR10## S-butyl-2-(phenyl)-tetrahydrothiopheniumhexafluoroantimonate, S-butyl-2-(4-methylphenyl)-tetrahydrothiopheniumhexafluorophospate,

S-butyl-2-(4-methyoxyphenyl)-tetrahydrothiophenium hexafluoroantimonate,

S-dodecyl-2-(4-methylphenyl)-tetrahydrothiophenium hexafluorophosphate,

S-butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium tetrafluroborate,

S-butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium perchlorate,

S-butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium triflate,

S-butyl-2-(4-isopropylphenyl)-tetrahydrothiophenium hexafluorophosphate,

S-butyl-2-(4-tert-butylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-butyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-tert-butyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-iso-butyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-iso-propyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-dodecyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-phenyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-butyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafluoroantimonate,

S-butyl-2-(2-methyl-4-methoxyphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-butyl-2-(2,4-dimethoxyphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-butyl-2-(2,4,6-trimethylphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-butyl-2-(2,6-dimethyl-4-methoxyphenyl)-tetrahydrothiopheniumhexafluorophosphate,

S-butyl-2-(4-methoxyphenyl)-pyranium hexafluorophosphate,

S,S'-ethylene-1,2-bis[2-(4-methoxyphenyl)-tetrahydrothiopheniumhexafluorophospate],

S,S'-hexylene-1,6-bis[2-(4-methoxyphenyl)-tetrahydrothiopheniumhexafluorophospate],

S,S'-p-xylylene-bis[2-(4-methoxyphenyl)-tetrahydrothiopheniumhexafluorophospate], and ##STR11##S-Butyl-2-phenyl-[3,4]-benzo-2,5-dihydro-thiopheniumhexafluorophosphate,S-Butyl-2-iso-propyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate,

S-Butyl-2,2-dimethyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate,

S-Butyl-2-metyl-2-phenyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate,

S-Butyl-2,2-diphenyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate, and ##STR12## S-Butyl-5-methyl-[3,4]-benzo-2,7-dihydrothiepinium hexafluorophosphate,S-Butyl -5-phenyl-[3,4]-benzo-2,7-dihydrothiepinium hexafluorophosphate.

Best mode of operation

The best mode of operation of the process according to the the presentinvention is to react an alkyl mercaptan, such as for example n-butyl-,iso-butyl-, sec-butyl-, or t-butyl mercaptan, with a 1-aryl substituted1,4-diol or a 2-aryl substituted tetrahydrofuran, preferably the diolsince the diols generally are more easily accessible, and a strongprotonic acid, in which the corresponding base is non-nucleophilic.Examples of non-nuclephilic anions are: hexafluorophosphate,hexafluoroantimonate, hexafluoroarsenate, and tetrafluoroborate,preferably hexafluorophosphate and hexafluoroantimonate.

The aryl substituent is preferably phenyl, which is unsubstituted ormono- or independently polysubstituted by C₁ -C₄ alkyl and/or C₁ -C₄alkoxy. Examples of such aryl substituens are phenyl, 4-methylphenyl,4-methoxyphenyl, 2,4-dimethylphenyl, 2-methyl-4-methoxyphenyl, and2,6-dimethyl-4-methoxyphenyl.

The reaction is performed by slowly adding aqueous HPF₆ (60% w/w, 1.5eq) to an ice-cooled mixture of the diol (1.0 eq.) and the mercaptan(1.0 eq.). The reaction mixture is stirred (2-24 h) at room temperature(20°-30° C.) under a N₂ -atmosphere. Then water (200 mL/mol diol) isadded and the resulting slurry is filtrated. The crystals are washedwith water (200 mL/mol in portions) and aqueous NaHCO₃ (100 mL/mol diolin portions). The crude material is recrystallized in ethanol (99.5%,0.7-1 l/kg crude material).

DESCRIPTION OF THE FIGURES

The invention is illustrated by the enclosed FIGS. 1 and 2.

FIG. 1 shows the intermediates of the cyclization-reaction of1-(2,4-dimethylphenyl)-1,4-butanediol 6f with n-butyl mercaptan in thepresence of 31% w/w of HPF₆ at 25° C., as studied by ¹ H-NMR as theconversion vs time. FIG. 1 clearly shows the transformation of 6f to thecorresponding sulfonium saltS-butyl-2-(2,4-dimethylphenyl)-tetrahydthiophenium hexafluorophosphate1f-(S-Bu)-PF₆ via the intermediate tetrahydrofuran 7f and sulfidoalcohol8f. (For further experimental details, see examples 36 and 37). Thismeans, as previously described herein, that either a diol or thecorresponding cyclic ether can be used as one of the reactants in thereaction according to the process of the present invention. Thetransformation of the diol to the cyclic ether is momentaneous under thepresent conditions.

FIG. 2 shows how the rate of formation of 1f-(S-Bu)-PF₆ is affected bydilution of HPF₆ with water. As expected the overall reaction rate isvery dependant on the proton activity. A two-fold dilution result in a400-fold decrease of the reaction rate.

The process according to the invention is further demonstrated by thefollowing examples. It should be understood that the examples areillustrative and not limitative. Percentage are given by weight unlessotherwise specified.

EXAMPLES

The cyclic sulfonium salts synthesized using the process of thisinvention in the examples are of the general structures 1, 2, 3, 4, and5.

    __________________________________________________________________________     ##STR13##                                                                                        ##STR14##                                                                            ##STR15##                                                                                   ##STR16##                            (R.sup.7).sub.y                R.sup.2(1)                                                                        R.sup.2(2) R.sup.2                         __________________________________________________________________________    1a                                                                              H                       3A   H   H     5A   Me                              1b                                                                              4-Me                    3B   H   Ph   5B    Ph                              1c                                                                              4-MeO                   3C   H   i-Pr                                       1d                                                                              4-i-Pr                  3D   Me  Me                                         1e                                                                              4-t-Bu                  3E   Me  Ph                                         1f                                                                              2,4-diMe    n = 1       3F   Ph  Ph                                         1g                                                                              2-Me, 4-MeO             4    H   H                                          1h                                                                              2,4-diMeO               For compounds 2-5 X = PF.sub.6                      1i                                                                              2,4,6-triMe             and for 3-5 R.sup.1 = n-Bu and                      1j                                                                              2,4-diMe-4-MeO          for 2 R.sup.1 = Benzyl                              1k                                                                              4-MeO (n = 2)                                                               For compounds 1 R.sup.1 = primary, secondary,                                 and tertiary alkyl, phenyl, (CH.sub.2).sub.2 ,                                (CH.sub.2).sub.6 , and p-xylylene                                             __________________________________________________________________________

Synthesis of cyclic sulfonium salts of type 1.

1-Aryl-1,4-butane-diols 6a-j and 1-(p-MeO-phenyl)-1,5-pentandiol 6k weretransformed to S-alkyl-2-aryl-tetrahydrothiophenium salts 1 by reactionwith a mercaptane in the presence of between 1.2-5 equivalents of theacid HX (where X=PF₆, SbF₆, BF₄, ClO₄, and CF₃ SO₃). The reaction wasperformed at 25° C. or slightly above utilizing the commercial acid asthe solvent or a two-phase system consisting of the commercial acid andmethylene chloride. When using commercially hexafluorophosphoric acid,which is stabilized by approximative 10% w/w of hydrogen fluoride, thereactions were performed in polyethylene or polypropylene bottles.Utilizing glassflasks results in partial formation of sulfonium saltshaving fluorosilicates as the counter ion, see for example Christie et.al. J. Am. Chem. Soc. 1990, 112, 7619. The results are summarized intable 1. The salts 1 are crystallinic materials isolated as mixture ofdiastereomers typically in a 1:1.5 ratio. The workup was achieved byeither diluting the reaction mixture with water followed by filtrationof the crystallinic sulfonium salt or by extraction with methylenechloride. The reactions proceed very cleanly and usually yield purecrude products. Most of the salts however, are easily recrystallizedfrom ethanol and in several cases crystallization afforded purediastereomers where the transisomer precipitates first. The majordiastereomer 1c(S-Me)-PF₆ was unambigously determined bye differentialNOE-NMR techniques to the trans-isomer. Irradiaton of the Me-S group inthe major isomer resulted in 21% enhancement whereas irraditon of theMe-S group in the minor gave less than 3% enhancement.

                                      TABLE 1                                     __________________________________________________________________________    (R.sup.7).sub.y                                                                        Diol/Ether                                                                          Conditions.sup.i                                                                    Sulfonium salt                                                                         Yield % (trans/cis)                             __________________________________________________________________________    H        6 a   A   24 h                                                                            1a(S--Bu)--PF.sub.6                                                                    94.sup.ii (1.8/)                                H        6 a   B   60 h                                                                            1a(S--Bu)--SbF.sub.6                                                                   82 [65].sup.ii (2.7/1)                          4-Me     6 b   A   24 h                                                                            1b(S--Bu)--PF.sub.6                                                                    84 (1.4/1)                                      4-MeO    7 c   A   24 h                                                                            1c(S--Bu)--PF.sub.6                                                                    100 [78].sup.ii (6.7/1)                         4-MeO    7 c   B   24 h                                                                            1c(S--Bu)--SbF.sub.6                                                                   82 [66].sup.ii (3.0/1)                          4-i-Pr   6 d   A   24 h                                                                            1d(S--Bu)--PF.sub.6                                                                    58 (1.5/1)                                      4-t-Bu   6 e   A   24 h                                                                            1e(S--Bu)--PF.sub.6                                                                    51 (2/1)                                        2,4-diMe 7 f   A   17 h                                                                            1f(S--Bu)--PF.sub.6                                                                    100 [70].sup.ii (1/1)                           2,4-diMe 6 f   B   24 h                                                                            1f(S--Bu)--SbF.sub.6                                                                   69 [51].sup.ii (4/1)                            2-Me, 4-MeO                                                                            6 g   A   17 h                                                                            1g(S--Bu)--PF.sub.6                                                                    76 [42].sup.ii (1.7/1)                          2,4-diMeO                                                                              6 h   A   16 h                                                                            1h(S--Bu)--PF.sub. 6                                                                   66 (3.7/1)                                      2,4,6-triMeO                                                                           6 i   A   24 h                                                                            1i(S--Bu)--PF.sub.6                                                                    59 (>10/1)                                      2,6-diMe, 4-MeO                                                                        6 j   A   4 h                                                                             1j(S--Bu)--PF.sub.6                                                                    98 [43].sup.ii (>10/1)                          4-MeO    6 k   A  120 h                                                                            1k(S--Bu)--PF.sub.6                                                                    32 (>10/1).sup.iii                              __________________________________________________________________________     .sup.i Conditions A: BuSH (1.4-1.5 eq), acid (1.4-2.0 eq), CH2Cl2 (0.2-1      mL/mmol 2); Conditions B: BuSH (1.0 eq), acid (2.0 eq).                       .sup.ii Yield after one recrystallization in EtOH.                            .sup.iii The reaction was quenched after 52% conversion and the salt was      accompanied with 5(4-MeO-Phenyl)-5-BuS-pentan-1-ol.                      

The reaction is general with respect to the substituent R¹ includingdimercaptans allowing synthesis of bis-sulfonium salts, see table 2. Thereaction was also examined for a number of different mineral acids andthe results are shown in table 3.

The mechanism (scheme 1) of the reaction is a multistep event andincludes an immediate formation of the tetrahydrofuran derivative 7which after protonation regioselectively reacts at the benzylic positionto form the sulfido alcohol 8. The isomeric sulfidoalcohol 9 has notbeen observed in any of the cases we studied. The reaction can easily befollowed by ¹ H-NMR and the methine protons on 6, 7, and 1 together withthe methylene group CH₂ O in 8 are easily distinguished. ##STR17##Synthesis of the diols 6 was achieved by a two-step procedure, scheme 2,These methods are literature procedures starting with AlCl₃ -catalyzedFriedel-Crafts acylation of the appropriate aromatic compound 10 withsuccinic anhydride or glutaric anhydride to form the ω-aroyl-carboxylicacids 11, see Olah, G. A. Friedel-Crafts Chemistry John Wiley 1973 91 ffand Olah, G. A. Friedel-Crafts and Related Reactions John Wiley 1964, 3,551 ff; Tamura, Y. Yakura, T., Yoshiaki, Y, Haruta, J. Chem. Pharm.Bull. 1985, 33, 1097.

Friedel-Crafts acylations are often performed in solvents such asnitrobenzene, CS₂, and chlorinated hydrocarbons. We have used thearomatic hydrocarbon 10 as the solvent for the acylation, see Fieser, L.F. and Seligman, A. M. J. Am. Chem. Soc. 1938, 60, 170. The acids 11were then reduced to the diols 6 with LiAlH₄ applying standardmethodology, see for example Fieser. L. F. and Fieser, M. Reagents forOrganic Synthesis John Wiley 1967, 1,584. ##STR18## Synthesis ofbenzofused cyclic sulfonium salts of type 3, 4 and 5.

Substituted benzenedimethanols 12 and 13 reacted smoothly with BuSH(n-butylmercaptan=n-butanethiol) in hexafluorophosphoric acid to thesulfonium salts 3, 4, and 5, see eqation 3. The results are summarizedin table 4. ##STR19## The diols 12 were synthesized via a generalorganometallic route starting from phthalide, eq 4. Grignard reagentswere utilized for preparation of compounds 12 (R²(1) =R²(2)) analogouslyto the procedures reported in: Smith, J. G. and Wikman, R. T.Tetrahedron 1974, 30, 2603 and Rickborn, B et. al. J. Org. Chem. 1989,54, 4253. The diols 8 (R²(1) ≠R²(2)) were prepared by mono addition ofan organolithium compound to ftalid followed by reaction with a grignardreagent (R²(2) ≠H) or LiAlH₄ (R²(2) =H). These two steps were performedin a one-pot procedure. Mono addition of R-Li to lactones to formlactoles have been shown previously, see for example Rickborn, Bet. al.J. Org. Chem. 1989, 54, 4253 and Bihovsky, R. and Rosenblum, S. B. J.Am. Chem. Soc. 1990, 112, 2746.

                  TABLE 2                                                         ______________________________________                                         ##STR20##                                                                     ##STR21##                                                                    Synthesis of 1f-PF.sub.6 and 1c-PF.sub.6 by variation of the                  mercaptan.sup.a                                                               Mercaptan     Reaction time.sup.b                                                                        Yield % (trans/cis)                                ______________________________________                                        n-Butylmercaptan.sup.c                                                                       1 h         95       (1.5/1)                                   n-Dodecylmercaptan.sup.c                                                                    20 h         73       (1.6/1)                                   i-Butylmercaptan.sup.c,d                                                                    24 h         94       (1.2/1)                                   i-Propylmercaptan.sup.c,d                                                                   24 h         87       (6.0/1)                                   t-Butylmercaptan.sup.c,d                                                                     5 h         96       (>39/1)                                   Phenylmercaptan.sup.c,e                                                                     100 h        88       (2/1)                                     1,2-Dimercaptoethane.sup.f,g                                                                 1 h         99                                                 1,6-Dimercaptohexane.sup.f,g                                                                 2 h         83                                                 p-Xylylene-α,α'-dithiol.sup.f,g                                                  4 h         86                                                 ______________________________________                                         .sup.a The reactions were performed in aqueous HPF.sub.6 (60% w/w; 1.5 eq     at 25° C. using 1.0 eq of mercaptan relative to the diol 6f.           .sup.b Refers to the time to workup.                                          .sup.c The product was a 1fPF.sub.6 sulfonium salt.                           .sup.d >95% conversion after 1 h.                                             .sup.e 65% conversion after 0.5 h.                                            .sup.f The cyclic ether 7c was used. The bissalts are a mixture of            theoretically 8 diastereomers.                                                .sup.g The product was a 1cPF.sub.6 sulfonium salt.                      

                  TABLE 3                                                         ______________________________________                                        Synthesis of 1c(S--Bu)--X from 7c by variation of the acid (HX).sup.a         HX       ([H.sup.+ ]).sup.b                                                                       Conditions.sup.c                                                                         Yield % (trans/cis)                            ______________________________________                                        HPF.sub.6                                                                              (60%, 7.4M)                                                                               3 h, 25° C..sup.d,g                                                              95 (1.5/1)                                     HSbF.sub.6.6H.sub.2 O                                                                  (5.8M)     20 h, 50° C..sup.e                                                                95 (5.3/1)                                     HBF.sub.4                                                                              (50%. 7.6M)                                                                              23 h, 50° C..sup.f,g                                                              88 (2.2/1)                                     HClO.sub.4                                                                             (70%, 10.5M)                                                                             24 h, 25° C.                                                                      95 (2/1)                                       CF.sub.3 SO.sub.3 H                                                                    (98%, 3.9M)                                                                              24 h, 50° C.                                                                      95 (2/1)                                       ______________________________________                                         .sup.a The reactions were performed in aqueous HX (1.5 eq) using 1.0 eq o     BuSH relative to the ether 7c.                                                .sup.b Formal molarity of the commercial acid HX.                             .sup.c Refers to the time to workup.                                          .sup.d 89% conversion after 1 h.                                              .sup.e 65% conversion after 0.5 h.                                            .sup.f 72% conversion after 24 h.                                             .sup.g The diol 6c was employed as the starting material.                

                  TABLE 4                                                         ______________________________________                                        Synthesis of the benzo-fused sulfonium salts 3, 4, and 5.                     R.sup.2(1)                                                                          R.sup.2(2)                                                                            Diol   Conditions.sup.a                                                                        Product                                                                              Yield %                                 ______________________________________                                        H     H       12A    66 h      3A     56                                      H     Ph      12B     7 h      3B     69.sup.b                                H     i-Pr    12C     6 h      3C     38.sup.c                                Me    Me      12D    50 h      3D     43                                      Me    Ph      12E    4.5 h     3E     73                                      Ph    Ph      12F    22 h      3F     60                                      vinyl Me      12G     6 h      5A     47                                      vinyl Ph      12J    5.5 h     5B     60                                      H     H       13      9 d      4      85                                      ______________________________________                                         .sup.a Conditions: BuSH (2.0 eq), HPF6 (3.5 eq) reactions were performed      at 25° C. and worked up after the time shown in the table.             .sup.b The crude product contained 8% of 3a and was 2.2/1 mixture of          diastereomers.                                                                .sup.c The product was obtained as 3.3/1 mixture of two diastereomers.        .sup.d The starting material was isochromane 13.                         

Experimental section including examples

General

NMR-spectra were recorded on a 200 MHz Bruker ACE spectrometer equippedwith a ¹ H/¹³ C-dual probe. Shifts are reported in ppm δ units relativeto tetramethylsilane (internal standard) and were recorded in CDCl₃ nototherwise noted. Melting points were recorded on a ElectrothermalDigital Melting Point Apparatous and are uncorrected. IR spectra wereobtained with a Perkin Elmer 1760 (FTIR) spectrometer. HPF₆ (60% in H₂O) and HSbF₆.H₂ O came from Ozark-Mahoning (Tulsa, Okla., 74107 U.S.A.).HBF₄ (48% in H₂ O), glutaric anhydride (98%), BuSH and MeMgCl (2M indiethylether) came from Merck. 3-Benzoylpropionic acid (11a),2-(Hydroxymethyl)-benzylalcohol (12a) and all other chemicals werepurchased from Aldrich Chemical Co. The cyclization reactions wereperformed in screwcapped polypropylene plastic bottles. Elementalanalysis were performed by Mikrokemi AB, Uppsala, Sweden. The followingabbreviations have been used: milliliter=mL, equivalents=eq. grams=g,tetrahydrofuran=THF.

General procedure for synthesis of sulfoniumsalts of type 1.

General procedure A

The acid (1.2-4.0 eq) was added slowly to an ice-cooled solution of diolor cyclic ether (1 eq) and BuSH (1.0-1.5 eq) in CH₂ Cl₂ (200-1000 mL/moldiol). The reaction mixture was stirred at the indicated time andtemperature under a N₂ -atmosphere. Water (200-1000 mL/mol diol) wasadded, the layers were separated and the aqueous-layer was extractedwith CH₂ Cl₂ (typically 3×50 mL/mol diol). The combined organic layerswere washed with water (typically 100 mL/mol diol) and aqueous NaHCO₃(saturated, 100 mL/mol diol), then dried (MgSO₄) and concentrated byrotary evaporation. Crude crystallinic products were recrystallized inEtOH (99.5%, 0.7-1 L/kg crude material). Sulfonium salt obtained as oilswere purified by: dissolving the crude oil in a small volume of CH₂ Cl₂and extracted 5-10 times with petroleumether (5 times the CH₂ Cl₂volume). Traces of mercaptan the product was removed by washing with aH₂ O₂ -solution [H₂ O₂ (35% w/w)/NaOH (2M) 1:4].

General procedure B

The reaction is performed by slowly adding the acid (1.2-4.0 eq) to anice-cooled mixture of the diol (1.0 eq) and the mercaptan (1.0 eq). Thereaction mixture is stirred at the indicated time and temperature(20°-50° C.) under a N₂ -atmosphere. Then water (200 mL/mol diol) isadded and the resulting slurry is filtrated. The crystals are washedwith water (200 mL/mol in portions) and aqueous NaHCO₃ (100 mL/mol diolin portions). The crude material is recrystallized in ethanol (99.5%,0.7-1 l/kg crude material).

Example 1

S-Butyl-2-(phenyl)-tetrahydrothiophenium hexafluorophosphate[1a(S-Bu)-PF_(6])

The diol 6a (415.5 g, 2.5 mol) was reacted with BuSH (316g. 3.5 mol) andaqueous HPF₆ (60%, 912 g, 3.75 g) in CH₂ Cl₂ (550 mL) for 24 h at RT(room temperature). Workup according to the general procedure A andrecrystallization in EtOH (700 mL) gave 860 g (94%) white crystals of1a(S-Bu)-PF₆ as a 1.8/1 mixture of diastereomers. Mp: 75°-80° C. ¹ H-NMR(aceton-d₆): 7.75-7.40 (m, Ar--H); 5.61 (dd, 1H, J=12.5 and 5.3 Hz,S--CH, minor isomer); 5.32 (dd, 1H. J=10.4 and 6.5 Hz, S--CH, majorisomer); 4.19-4.02 (m, CH₂ --S); 3.92-3.58 (m, CH₂ --S); 3.25-2.30 (m,CH--CH₂ --CH₂); 2.00-1.80 (m, CH₂ --CH₂ --CH₃); 1.58-1.15 (m, CH₂ -CH₃);0.91 (t, 3H, J=7.3 Hz, CH₃, major isomer); 0.72 (t, 3H, J=7.2 Hz, CH₃,minor isomer). ¹³ C-NMR (aceton-d₆): 135.30; 130.69; 130.02; 129.92;129.79; 128.80; 68.02; 64.65; 45.50; 44.30; 43.34; 39.10; 38.42; 31.47;29.37; 28.05; 27.41; 27.11; 21.67; 13.17; 13.03; Anal. Calcd for C₁₄ H₂₁SPF₆ : C, 45.90; H, 5.78; S, 8.75 Found: C, 45.8; H, 5.8; S, 8.2.

Example 2

S-Butyl-2-(phenyl)-tetrahydrothiophenium hexafluroantimonate[1a(S-Bu)-SbF₆ ]

HSbF₆.6H₂ O (876.5 g, 2.5 mol) was added to a mixture of diol 6a (208 g,1.25 mol) and BuSH (135 mL, 1.25 mol) kept at 10° C. The reactiontemperature was raised to 50° C. and the mixture was stirred for 60 h.H₂ O (300 mL) was added and two layers were formed. The aqueous-layer(+100 mL H₂ O) was extracted with CH₂ Cl₂ (2×100 mL). CH₂ Cl₂ (400 mL)was added to the organic layer and the layer was washed with H₂ O (100mL), Aqueous NaHCO3 (sat., 3×100 mL) and dried (MgSO₄). Evaporation gave467.3 g (82%). Recrystallisation in EtOH (2.6 L) gave 369 g (65%) ofwhite crystals 1a(S-Bu)-SbF₆ as a 2.7/1 mixture of diastereomers. Mp:57.2°-59.1° C. .sup. 1 H-NMR: Major isomer 7.43 (s, 5H, Ar--H); 5.01(dd, 1H, J=11.3 and 5.6 Hz, CH--S); 3.86-3.73 (m, 1H, S--CH₂); 3.63-3.52(m, 1H, S--CH₂); 3.40 (t, 2H, J=8 Hz, S--CH₂ CH₂); 2.90-2.29 (m, 4H,CH₂); 1.84-1.69 (m, 2H, CH₂); 1.52-1.35 (m, 2H, CH₂); 0.89 (t, 3H, J=7.3Hz, CH₃); Minor isomer (distinguishable peaks in mixture with majorisomer) 7.49 (s, 5H, Ar--H); 5.34 (dd, 1H, J=11.3 and 5.6 Hz, CH--S);4.02-3.89 (m, 1H, S--CH₂); 1.30-1.17 (m, 2H, CH₂); 0.72 (t, 3H, J= 7.1Hz, CH₃). ¹³ C-NMR: major isomer 132.91; 129.92; 129.73; 127.89; 68.97;43.81; 43.50; 38.74; 28.87; 27.15; 21.40; 13.11; Minor isomer 130.82;129.82; 129.24; 127.55; 65.30; 44.90; 38.64; 31.17; 28.06; 26.64; 21.34;13.00. IR: 1462; 1233; 730; 703; 659 cm⁻¹. Anal. Calcd for C₁₄ H₂₁ SSbF₆: C, 36.79; H, 4.63; S, 7.01. Found: C, 36.9; H, 4.7; S, 7.1.

Example 3

S-Butyl-2-(4-methylphenyl)-tetrahydrothiophenium hexafluorophosphate[1b(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 94.6 g, 0.39 mol) was added slowly to a mixture ofdiol 6b (50 g, 0.28 mol) and BuSH (25.06 g, 0.28 mol) kept at 0° C. andunder N₂ -atmosphere. The reaction mixture was stirred for 24 h at 25°C. H₂ O (500 mL) and CH₂ Cl₂ (100 mL) was added and the layers wereseparated. The aqueous-layer was extracted with CH₂ Cl₂ (2×20 mL). Thecombined organic layers were washed with aqueous NaHCO3 (sat., 2×20 mL)and dried (MgSO₄). Evaporation gave 89 g (84%) colorless oil of1b(S-Bu)-PF₆ as a 1.4/1 mixture of diastereomers. ¹ H-NMR: Major isomer7-34-7.19 (m, 4H, Ar--H); 5.04 (dd, 1H, J=11.1 and 6.3 Hz, CH--S);3.88-3.75 (m, 1H, CH₂ --S); 3.70-3.57 (m, 1H, CH₂ --S); 3.45 (t, 2H,J=7.5 Hz, S--CH₂ CH₂); 2.89-2.78 (m, 1H, CH₂); 2.68-2.49 (m, 2H, CH₂);2.49-2.22 (m, 1H, CH₂); 2.35 (s, 3H, CH₃ --Ar); 1.85-1.65 (m, 2H, CH₂);1.50-1.32 (m, 2H, CH₂); 0.89 (t, 3H, J=7.2 Hz, CH₃); Minor isomer(distinguishable peaks in mixture with major isomer) 5.50 (dd, 1H,CH--S); 2.37 (s, 3H, CH₃ --Ar); 0.73 (t, 3H, CH₃). ¹³ C-NMR: Majorisomer 140.00; 130.28 (2C); 129.95; 127.81 (2C); 66.72; 43.83; 43.18;38.64; 28.71; 27.14; 21.34; 21.18; 13.13; Minor isomer (distinguishablepeaks in mixture with major isomer) 141.05; 130.37 (2C); 129.12 (2C);124.58; 65.20; 45.56; 38.23; 31.20; 27.91; 26.62; 21.09: 13.06.

Example 4

S-Butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium hexafluorophosphate[1c(S-Bu)-PF₆ ]

The cyclic ether 7c (601 g, 3.37 mol) was reacted with BuSH (426 g, 4.72mol) and aqueous HPF₆ (60%, 1.23 kg, 5.05 mol) in CH₂ Cl₂ (750 mL) for24 h. Workup according to the general procedure A gave 1.33 kg (100%) ofcrude 1c(S-Bu)-PF₆ as a 1.5/1 mixture of diastereomers.Recrystallisation in EtOH (1 L) gave 1.038 kg (78%) white crystals of1c(S-Bu)-PF₆ as a 6.7/1 mixture of diastereomers. Mp: 83.7° C. ¹ H-NMR:Major isomer 7.38 (d, 2H, J=8.8 Hz, Ar); 6.91 (d, 2H, J=8.8 Hz, Ar);5.08 (dd, 1H, J=11 and 6 Hz, CH--S); 4.0-3.7 (m, 1H, CH₂ --S); 3.80 (s,3H, MeO); 3.65-3.5 (m, 1H, CH₂ --S); 3.42 (t, 2H, J=7.2 Hz. S--CH₂ CH₂CH₂ CH₃), 2.9-2.25 (m, 4H, CH₂); 1.75 (m, 2H, CH₂); 1.43 (m, 2H, CH₂);0.89 (t, 3H, J=7.3 Hz, CH₃); Minor isomer 7.43 (d, 2H, J=8.8 Hz, Ar);6.95 (d, 2H J=8.8 Hz, Ar); 5.38 (dd, 1H, J=11 and 6 Hz, CH₂ --S);4.0-3.7 (m, 1H, CH₂ --S); 3.83 (s, 3H, MeO); 3.65-3.5 (m, 1H, CH₂ --S);3.42 (t, 2H, J=7.2 Hz, S--CH₂ CH₂ CH₂ CH₃), 2.9-2.25 (m, 4H, CH₂);1.5-1.0 (m, 4H, CH₂); 0.75 (t, 3H, J=7.3 Hz, CH₃). ¹³ C-NMR: Majorisomer 160.64; 129.38 (2C); 124.55; 114.99 (2C); 69.05; 55.37; 43.43;43.08; 38.49; 28.64; 27.15; 21.35; 13.14; Minor isomer 161.29; 130.68(2C); 119.19; 115.05 (2C); 65.61; 55.43; 44.49; 38.17; 31.45; 27.93;26.64; 21.35; 13.08. IR (KBr, major+minor isomer): 1518; 1260; 1186; 832(PF₆ ⁻¹) cm⁻¹. Anal. Calcd for C₁₅ H₂₃ OSPF₆ : C, 45.45; H, 5.85; S,8.09.Found: C, 45.3; H, 5.9; S, 7.7.

Example 5

S-Butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium hexafluorophosphate[1c(S-Bu)-PF₆ ]

The diol 6c was reacted with BuSH (1 eq) and aqueous HPF₆ (60%, 1.5 eq)at 25° C. for 3 h according to procedure B. Extractive workup with CH₂Cl₂ according to procedure A afforded 95% of 1c(S-Bu)-PF₆ as a 1.5/1mixture of diastereomers.

Example 6

S-Butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium hexafluoroantimonate[1c(S-Bu)-SbF₆ ]

HSbF₆.H₂ O (106 g, 307.5 mmol) was added slowly to an ice-cooledsolution of cyclic ether 7c (27.4 g, 153.7 mmol) and BuSH (16.5 mL,153.7 mmol). The temperature was raised to 50° C. and the reactionmixture was stirred for 24 h. H₂ O (50 mL) and CH₂ Cl₂ (50 mL) was addedand the layers were separeted. The aqueous-layer was extracted with CH₂Cl₂ (2×40 mL). The combined organic layers were washed with aqueousNaHCO₃ (sat., 2×50 mL) and dried (MgSO₄). Evaporation gave 61.6 g (82%)of 1c(S-Bu)-SbF₆ as a colorless oil that crystallized slowly(diastereomer mixture 2.5/1). Recrystallization in EtOH (50 mL) gave49.4 g (66%) white crystals of 1c(S-Bu)-SbF₆ as a 3/1 mixture ofdiastereomers. Mp: 75°-77.1° C. ¹ H-NMR: Major isomer 7.37 (d, 2H, J=8.8Hz, Ar--H); 6.93 (d, 2H, J=8.8 Hz, Ar--H); 5.00 (dd, 1H, J=11.0 and 6.2Hz, S--CH); 3.86- 3.69 (m, 1H, S--CH₂); 3.80 (s, 3H, OCH₃); 3.59-3.49(m, 1H, S--CH₂); 3.43-3.34 (m, 2H, S--CH₂); 2.84-2.26 (m, 4H, CH₂);1.85-1.69 (m, 2H, CH₂); 1.55-1.35 (m, 2H, CH₂); 0.90 (t, 3H, J=7.2 Hz,CH₃); Minor isomer (distinguishable peaks in mixture with major isomer)7.43 (d, 2H, Ar--H); 6.96 (d, 2H, Ar--H); 5.33 (dd, 1H, J=11.7 and 6.0Hz; S--CH); 3.82 (s, 3H, OCH₃); 0.75 (t, 3H, J=7.3 Hz, CH₃). ¹³ C-NMR:Major isomer 160. 72; 129.35 (2C); 1124.29, 115.06 (2C); 69.47; 55.38;43.51; 43.31; 38.46; 28.73; 27.19; 21.38; 13.11; Minor isomer 161.37;130.69 (2C); 118.95; 115.12 (2C); 65.47; 55.44; 44.65; 31.53; 28.09;26.64; 21.41; 13.05. IR: 1612; 1517; 1469; 1258; 1233; 1185; 1029; 834;655 cm⁻¹. Anal. Calcd for C₁₅ H₂₃ OSSbF₆ : C, 36.98; H, 4.76; S, 6.58.Found: C, 37.0; H, 4.8; S, 6.6.

Example 7

S-Butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium hexafluoroantimonate[1c(S-Bu)-SbF₆ ]

The cyclic ether 7c was reacted with BuSH (1 eq) and HPSb₆.6H₂ O (1.5eq) at 50° C. for 20 h according to procedure B. Extractive workup withCH₂ Cl₂ according to procedure A afforded 95% of 1c(S-Bu)-SbF₆ as a5.3/1 mixture of diastereomers.

Example 8

S-Dodecyl-2-(4-methoxyphenyl)-tetrahydro-thiophenium hexafluorophosphate[1c(S-dodecyl)-PF₆ ]

Aqueous HPF₆ (60%, 7.3 g, 30 mmol) was added slowly to a solution ofdiol 6c (2.94 g, 15 mmol) and 1-dodecylmercaptan [1-dodecanthiol] (4.55g, 22.5 mmol) in CH₂ Cl₂ (20 mL). The reaction mixture was stirred for24 h. Workup according to the general procedure A gave 3.79 g (50%) of1c(S-dodecyl)-PF₆ as a 2/1 mixture of diastereomers. ¹ H-NMR: 7.53-7.45(dd, 2H, Ar--H); 6.95 (t, 2H, Ar--H); 5.45 (dd, 1H, CH--S, minorisomer); 5.20 (dd, 1H, CH--S, major isomer); 4.08-3.44 (m, 4H, CH₂ --S);3.83 (s, 3H, OCH₃, minor isomer); 3.81 (s, 3H, OCH₃, major isomer);3.05-2.55 (m, 4H, CH--CH₂ --CH₂ --S); 1.87-1.7 (m, CH₂); 1.5-0.9 (m,20H, CH₂); 0.87 (t, 3H, CH₃ --CH₂);

Example 9

S-Butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium tetrafluoroborate[1c(S-Bu)-BF₄ ]

Aqueous HBF₄ (50%, 8.23 g, 45 mmol) was added to a mixture of diol 6c(5.89 g, 30 mmol) and BuSH (2.71 g, 30 mmol). The reaction mixture wasstirred for 3 h at RT and for 20 h at 50° C. CH₂ Cl₂ (10 mL) was addedand the layers were separated. The aqueous-layer was extracted with CH₂Cl₂ (10 mL). The combined organic layers were washed with aqueous NaHCO₃(sat., 10 mL), H₂ O (5 mL) and dried (MgSO₄). Evaporation gave 8.91 g(88%) of 1c(S-Bu)-BF₄ as a 2.2/1 mixture of diastereomers. ¹ H-NMR:Major isomer 7.43 (d, 2H, Ar--H); 6.91 (d, 2H, Ar--H); 5.22 (dd, 1H,CH--S); 4.05-3.40 (m, 7H, including CH₂ --S(ring), 2 H, 3.80 (s, 3H, CH₃O), and 3.50 (t, 2H, CH₂ S)); 3.06-2.20 (m, 4H, CH₂ (ring)); 1.78 (m,2H, CH₂ CH₂ CH₃); 1.44 (m, 2H, CH₂ CH₃); 0.89 (t, 3H, CH₂ CH₃); Minorisomer (distinguishable peaks in mixture with major isomer) 7.48 (d,Ar--H); 6.95 (d, Ar--H); 5.47 (dd, CH₂ --S); 3.82 (s, CH₃ O); 0.75 (t,CH₂ CH₃). ¹³ C-NMR: Major isomer 160.47; 129.50 (2C); 124.97; 114.85(2C); 68.54; 55.32; 43.57; 42.99; 8.54; 28.59; 27.18; 21.35; 13.18;Minor isomer (distinguishable peaks in mixture with major isomer)161.13; 130.76 (2C); 119.62; 114.90 (2C); 65.36; 55.39; 44.53; 37.90;31.48; 7.92; 26.69; 21.35; 13.11.

Example 10

S-Butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium perchlorate[1c(S-Bu)-ClO₄ ]

Aqueous HClO₄ (70%, 2.153 g, 15 mmol) was added to a mixture of cyclicether 7c (1.782 g, 10 mmol) and BuSH (0.902 g, 10 mmol). The temperaturewas raised to 50° C. and the reaction mixture was stirred for 24 h. H₂ O(5 mL) and CH₂ Cl₂ (10 mL) was added and the layers were separated. Theaqueous-layer was extracted with CH₂ Cl₂ (2×5 mL). The combined organiclayers were washed with aqueous NaHCO₃ (sat., 5 mL), H₂ O (5 mL) anddried (MgSO₄). Evaporation gave 3.34 g (95%) oil of 1c(S-Bu)ClO₄ as a2/1 mixture of diastereomers. ¹ H-NMR: Major isomer 7.42 (d, 2H, Ar--H);6.93 (d, 2H, Ar--H); 5.27 (dd, 1H, CHS); 4.10-3.50 (m, 7H, including CH₂S (ring), 2H, 3.81 (s, 3H, CH₃ O), and 3.57 (t, 2H, CH₂ S)); 3.10-2.30(m, 4H, CH₂ (ring)); 2.80 (m, 2H, CH₂ CH₂ CH₃); 1.47 (m, 2H, CH₂ CH₃);0.91 (t, 3H, CH₂ CH₃); Minor isomer (distinguishable peaks in mixturewith major isomer) 7.48 (d, Ar--H); 6.97 (d, ArH); 5.51 (dd, CHS); 3.83(s, CH₃ O); 1.25 (m, CH₂ CH₃); 0.76 (t, CH₂ CH₃). ¹³ C-NMR: Major isomer160.41; 129.41 (2C); 124.73; 114.80 (2C); 68.52; 55.26; 43.71; 43.07;38.53; 28.66; 7.13; 21.31; 13.06; Minor isomer (distinguishable peaks inmixture with major isomer) 161.05; 130.67 (2C); 119.44; 114.79 (2C);65.44; 55.31; 44.60; 38.00; 31.55; 27.98; 26.61; 21.31; 13.15.

Example 11

S-Butyl-2-(4-methoxyphenyl)-tetrahydrothiophenium triflate [1c(S-Bu)-CF₃SO₃ ]

CF₃ SO₃ H (98%, 2.25 g, 15 mmol) was added to a mixture of cyclic ether7c (1.782 g, 10 mmol) and BuSH (0.902 g, 10 mmol). The reactiontemperature was raised to 50° C. and the mixture was stirred for 24 h.H₂ O (5 mL) and CH₂ Cl₂ (10 mL) was added and the layers were separated.The aqueous-layer was extracted with CH₂ Cl₂ (2×5 mL). The combinedorganic layers were washed with aqueous NaHCO₃ (sat., 5 mL), H₂ O (5 mL)and dried (MgSO₄). Evaporation gave 3.80 g (95%) oil of 1c(S-Bu)-CF₃ SO₃as a 2/1 mixture of diastereomers. ¹ H-NMR: Major isomer 7.42 (d, 2H,Ar--H); 6.92 (d, 2H, Ar--H); 5.30 (dd, 1H, CHS); 4.05-3.50 (m, 7H,including CH₂ S(ring), 2H, 3.81 (s, 3H, CH₃), and 3.57 (t, 2H, CH₂ S));3.10-2.20 (m, 4H, CH₂ (ring)); 1.76 (m, 2H, CH₂ CH₂ CH₃); 1.44 (m, 2H,CH₂ CH₃); 0.90 (t, 3H, CH₂ CH₃); Minor isomer (distinguishable peaks inmixture with major isomer) 7.48 (d, Ar--H); 6.96 (d, Ar--H); 5.53 (dd,CH₂ S); 3.83 (s, CH₃ O); 0.76 (t, 3H, CH₂ CH₃). ¹³ C-NMR: Major isomer160.36; 129.27 (2C); 124.63; 123.71 (triflate); 114.72 (2C); 68.22;55.16; 43.57; 42.86; 38.38; 28.40; 27.05; 21.17; 12.92; Minor isomer(distinguishable peaks in mixture with major isomer) 160.98; 130.56(2C); 119.41; 117.34 (triflate); 114.72 (2C); 65.33; 52.21; 44.45;37.81; 31.44; 27.83; 26.49; 21.17; 13.00.

Example 12

S-Butyl-2-(4-isopropylphenyl)-tetrahydrothiophenium hexafluorophosphate[Id(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 2.92 g, 12 mmol) was added slowly to a solution ofdiol 6d (1.25 g, 6 mmol) and n-butylmercaptan (0.81 g, 9 mmol) in CH₂Cl₂ (8 mL). The reaction mixture was stirred for 24 h. Workup accordingto the general procedure A gave 1.42 g (58%) brown oil of 1d(S-Bu)-PF₆as a 1.5/1 mixture of diastereomers. 100 mg of 1d(S-Bu)-PF₆ was washedwith a H₂ O₂ -solution and to give a colorless oil. ¹ H-NMR: 7.50-7.13(m, 4H, Ar--H); 5.40 (dd, 1H, CH--S, minor isomer); 5.16 (dd, 1H, CH--S,major isomer); 4.13-3.45 (m, CH₂ --S); 3.06-2.20 (m, CH--CH₂ --CH₂ andCH(CH₃)₂); 1.85-1.1 (m, CH₂ --CH ₂ --CH₃); 1.24 (d, 6H, (CH₃)₂ CH); 0.91(t,3H, CH₃ --CH₂, major isomer); 0.71 (t, 3H, CH₃ --CH₂, minor isomer).

Example 13

S-Butyl-2-(4-tertbutylphenyl)-tetrahydro-thiophenium hexafluorophosphate[1e(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 2.92 g, 12 mmol) was added slowly to a solution ofdiol 6e (1.33 g, 6 mmol) and BuSH (0.81 g, 9 mmol) in CH₂ Cl₂ (8 mL)kept at 0° C. The reaction mixture was stirred for 24 h. Workupaccording to the general procedure A gave 1.28 g (51%) yellow oil of1e(S-Bu)-PF₆ as a 2/1 mixture of diastereomers. ¹ H-NMR: 7.53-7.17 (m,4H, Ar--H); 5.47 (dd, 1H, CH--S, minor isomer); 5.20 (dd, 1H, CH--S,major isomer); 4.16-3.46 (m, CH₂ --S); 3.12-2.24 (m, CH--CH₂ --CH₂);2.02-0.8 (m, CH₂ --CH₂ --CH₃); 1.31.(s+s, 9H, (CH₃)₃ C); 0.91 (t, 3 H,CH₃ --CH₂, major isomer); 0.70 (t, 3H, CH₃ --CH₂, minor isomer).

Example 14

S-Butyl-2-(2,4-dimethylphenyl)-tetrahydrothiophenium hexafuorophosphate[1f(S-Bu)-PF₆ ]

The cyclic ether 7f (476 g, 2.7 mol) was reacted with BuSH (341 g, 3.78mol) and aqueous HPF₆ (60%, 985 g, 4.05 mol) in CH₂ Cl₂ (600 mL) and thereaction mixture was stirred for 17 h at RT. Workup according to thegeneral procedure A gave 1.065 kg (100%) of crude 1f(S-Bu)-PF₆.Recrystallization in EtOH (920 mL) gave 745 (70%) white crystals of1f(S-Bu)-PF₆ as a 1/1 mixture of diastereomers. ¹ H-NMR (aceton-d₆):7.63 (d, 1H, Ar--H, major isomer); 7.49 (d, 1H, Ar--H, minor isomer);7.27-7.13 (m, 2H, Ar--H); 5.65 (dd, 1H, J=12.5 and 5.0 Hz, CH--S, majorisomer); 5.54 (dd, 1H, J=10.2 and 6.8 Hz, CH--S, minor isomer);4.24-3.62 (m, CH₂ --S); 3.20-2.25 (m, CH--CH₂ --CH₂); 2.47 (s, 3H,Ar--CH₃, major isomer); 2.45 (s, 3H, Ar--CH₃, minor isomer); 2.35 (s,3H, Ar--CH₃, major isomer); 2.31 (s, 3H, Ar--CH₃, minor isomer); 1.90(m, CH₂); 1.6-0.8 (m, CH₂ --CH₂ --CH₃); 0.95 (t, 3H, C₂ --CH₃, minorisomer); 0.74 (t, 3H, CH₂ --CH₃, major isomer). ¹³ C-NMR: 131.98;128.00; 127.89; 127.52; 64.95; 62.46; 44.61; 43.55; 42.81; 38.50; 38.31;31.40; 28.56; 27.34; 26.56; 21.25; 20.93; 19.34; 13.03. Anal. Calcd forC₁₆ H₂₅ SPF₆ : C, 48.73; H, 6.39; S, 8.13. Found: C, 48.8; H, 6.5; S,7.8

Example 15

S-tert-Butyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafuorophosphate [1f(S-tert-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 10.95 g, 45 mmol) was added to a mixture of diol 6f(5.82 g, 30 mmol) and t-BuSH (2.71 g, 30 mmol). After 2 hours' stirring,crystallization started. H₂ O (15 mL) was added, the crystals werefiltrated and washed with H₂ O (2×10 mL), aqueous NaHCO₃ (sat., 2×10 mL)and H₂ O (10 mL). The crystals were dried to give 10.59 g (90%) whitecrystals of 1f(S-tBu)-PF₆ as a >30/1 mixture of two diastereomers. ¹H-NMR: 7.36 (d, 1H, Ar--H); 7.06 (d, 1H, Ar--H), 7.02 (s, 1H, Ar--H);5.06 (dd, 1H, CHS); 3.86-3.52 (m, 2H, CH₂ S); 2.82-2.05 (m, 10H,including CH₂ (ring), 4H, 2.42 (s, 3H, CH₃ Ar), and 2.28 (s, 3H, CH₃Ar)); 1.54 (s, 9H, t-Bu). ¹³ C-NMR: 137.79; 136.24; 135.65; 131.11;126.98; 126.68; 48.49; 38.68; 33.19; 30.88; 20.97; 19.69.

Example 16

S-iso-Butyl-2-(2,4-dimethylphenyl)-tetrahydrothiopheniumhexafuorophosphate [1f(S-iso-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 10.95 g, 45 mmol) was added to a mixture of diol 6f(5.82 g, 30 mmol) and 1-BuSH (2.71 g, 30 mmol). The reaction mixture wasstirred for 24 h. H₂ O (10 mL) was added and crystallization started.The crystals were filtrated and washed with H₂ O (2×5 mL), aqueousNaHCO₃ (2×5 mL) and H₂ O (5 mL). Drying gave 11.14 g (94%) of1f(S-iso-Bu)-PF₆ as a 1.2/1 mixture of diastereomers. ¹ H-NMR: Majorisomer 7.39 (d, 1H, Ar--H); 7.10 (s, 1H, Ar--H); 7.07 (d, 1H, Ar--H);5.34 (dd, 1H, CHS); 4.12-3.35 (m, 4H, including CH₂ (ring), 2H, and 3.38(d, 2H, CHCH₂ S )); 2.96-2.54 (m, 4H, CH₂ (ring)); 2.43 (s, 3H, CH₃ Ar);2.34 (s, 3H, CH₃ Ar); 1.33 (m, 1H, CH₃ CH); 0.92 (d, 3H, CH₃ CH); 0.78(d, 3H, CH₃ CH); Minor isomer (distinguishable peaks in mixture withmajor isomer) 7.25 (d, Ar--H); 5.22 (dd, CHS); 2.39 (s, CH₃ Ar); 2.30(s, CH₃ Ar); 2.06 (m, CH₃ CH); 1.08 (d, CH₃ CH); 1.01 (d, CH₃ CH). ¹³C-NMR: Major isomer 141.00; 137.96; 132.27; 128.18; 127.73; 123.12;63.04; 46.98; 45.31; 31.63; 27.41; 26.42; 25.52; 21.11; 21.04 (2C);Minor isomer (distinguishable peaks in mixture with major isomer)139.56; 135.93; 132.18; 128.45; 128.09; 127.47; 66.17; 51.76; 44.02;38.57; 28.74; (25.52); 21.39; 20.91; 19.31 (2C).

Example 17

S-iso-Propyl-2-(2,4-dimethylphenyl)tetrahydrothiopheniumhexafuorophosphate [1f(S-iso-Pr)-PF₆ ]

Aqueous HPF₆ (60%, 10.95 g, 45 mmol) was added to a mixture of diol 6f(5.82 g, 30 mmol) and i-PrSH (2.28 g, 30 mmol). The reaction mixture wasstirred for 24 h. H₂ O (10 mL) and CH₂ Cl₂ (50 mL) was added and thelayers were separated. The aqueous-layer was extracted with CH₂ Cl₂(2×10 mL). The combined organic layers were washed with aqueous NaHCO₃(sat., 2×10 mL) and dried (MgSO₄). Evaporation gave 9.92 g (87%) of1f(S-iso-Pr)-PF₆ as a 6/1 mixture of diastereomers. ¹ H-NMR: Majorisomer 7.26 (d, 1H, Ar--H); 7.07 (d, 1H, Ar--H); 7.04 (s, 1H, Ar--H);5.25 (dd, 1H, CHS(ring)); 4.06-3.57 (m, 3H, CH₂ S and CH₃ CH); 2.93-2.14(m, 10H, including CH₂ (ring), 4H, 2.42 (s, 3H, CH₃ Ar), and 2.30 (s,3H, CH₃ Ar)); Minor isomer (distinguishable peaks in mixture with majorisomer) 7.50 (d, Ar--H); 5.36 (dd, CHS(ring)); 3.35 (m, CH₃ CH); 2.45(s, CH₃ Ar); 0.56 (d, CH₃ CH). ¹³ C-NMR: Major isomer 139.45; 135.54;132.21; 128.58; 128.14; 127.97; 64.37; 48.76; 41.29; 38.89; 28.66;20.85; 19.69; 19.20; 18.76; Minor isomer (distinguishable peaks inmixture with major isomer) 141.05; 138.24; 123.55; 64.09; 44.11; 41.65;32.21; 27.00; 19.32; 19.02; 18.92.

Example 18

S-Dodecyl-2-(2,4-dimethylphenyl)-tetrahydro-thiopheniumhexafuorophosphate [1f(S-dodecyl)-PF₆ ]

Aqueous HPF₆ (60%, 7.30 g, 30 mmol) was added to a mixture of diol 6f(3.89 g, 20 mmol) and n-dodecylmercaptan (4.05 g, 20 mmol). The reactionmixture was stirred for 24 h. H₂ O (10 mL) was added and the layers wereseparated. The aqueous-layer was extracted with CH₂ Cl₂ (2×10 mL), thecombined organic layers were washed with H₂ O (5 mL) and aqueous NaHCO₃(sat., 5 mL) and dried (MgSO₄). Evaporation and extractions withpetroleumether gave 7.38 g (73%) colorless oil of 1f(S-dodecyl)-PF₆ as a1.6/1 mixture of diastereomers. ¹ H-NMR: Major isomer 7.39 (d, 1H,Ar--H); 7.10 (s, 1H, Ar--H); 7.07 (d, 1H, Ar--H); 5.34 (dd, 1H,CHS(ring)); 4.09-3.40 (m, 4H, CH₂ S); 2.90-2.20 (m, 10H, inclusing CH₂(ring), 4H, 2.44 (s, 3H, CH₃ Ar), and 2.34 (s, 3H, CH₃ Ar)); 1.45-1.00(m, 18H, CH₂); 0.87 (d, 3H, CH₃ CH₂); Minor isomer (distinguishablepeaks in mixture with major isomer) 7.24 (d, Ar--H); 5.20 (dd,CHS(ring)); 2.41 (s, CH₃ Ar); 2.31 (s, CH₃ Ar). ¹³ C-NMR: 140.72;139.38; 137.90; 135.72; 132.01; 128.29; 127.95; 127.82; 127.60; 127.46;122.99; 65.49; 62.62; 44.60; 43.39; 38.92; 38.34; 31.65; 31.29; 29.33;29.17; 29.08; 28.85; 28.79; 28.62; 28.48; 27.83; 27.21; 25.29; 24.61;22.43; 20.85; 20.74; 19.20; 13.85.

Example 19

S-Phenyl-2-(2,4-dimethylphenyl)-tetrahydro-thiopheniumhexafuorophosphate [1f(S-Ph)-PF₆ ]

Aqueous HPF₆ (60%, 10.95 g, 45 mmol) was added to a mixture of diol 6f(5.82 g, 30 mmol) and thiophenol (3.31 g, 30 mmol). The reaction mixturewas stirred for 100 h. H₂ O (15 mL) was added and the layer was decantedand extracted with CH₂ Cl₂ (2×3 mL). The combined organic layers weredissolved in CH₂ Cl₂ (80 mL), washed with aqueous NaHCO₃ (sat., 2×10 mL)and dried (MgSO₄). Evaporation gave 10.88 g (88%) of 1f(S-Ph)-PF₆ as a2/1 mixture of diastereomers. ¹ H-NMR (CDCl₃ +DMSO-D₆); Major isomer7.90-6.43 (m, 8H, Ar--H); 5.69 (dd, 1H, ArCHS); 4.47-3.93 (m, 2H, CH₂S); 3.11-2.46 (m, 7H, including CH₂ (ring), 4H, and 2.52 (s, 3H, CH₃Ar)); 2.20 (s, 3H, CH₃ Ar); Minor isomer (distinguishable peaks inmixture with major isomer) 5.56 (dd, ArCHS); 2.31 (s, CH₃ Ar); 1.98 (s,CH₃ Ar).

Example 20

S-Butyl-2-(2,4-dimethylphenyl)-tetrahydro-thiopheniumhexafluoroantimonate [1f(S-Bu)-SbF₆ ]

HSbF₆.H₂ O (535 g, 1.545 mol) was added to a mixture of diol 6f (200 g,1.03 mol) and BuSH (111 mL, 1.03 mol) kept at 20°-25° C. The reactiontemperature was raised to 50° C. and the mixture was stirred for 24 h.H₂ O (150 mL) was added and the aqueous-layer decanted. CH₂ Cl₂ (500 mL)was added to the organic layer, washed with H₂ O (400 mL), aqueousNaHCO₃ (200 mL) and dried (MgSO₄). Evaporation gave 346.8 g (69%) of 1f(S-Bu)-SbF₆ as a 1/1 mixture of diastereomers. Recrystallisation in EtOH(1 L) gave 256.5 g (51%) white crystals of 1f(S-Bu)-SbF₆ as a 4/1mixture of diastereomers. Mp: 99.1°-101° C. ¹ H-NMR: Major isomer 7.39(d, 1H, J=8.5 Hz, Ar--H); 7.12 (s, 2H, Ar--H); 5.31 (dd, 1H, J=12.2 and4.8 Hz, SCH); 4.05-3.94 (m, 1H, SCH₂ CH₂ CH₂ CH₃); 3.50-3.32 (m, 1H,SCH₂); 2.89-2.59 (m, 4H, CH₂); 2.43 (s, 3H, Ar--CH₃); 2.34 (s, 3H,Ar--CH₃); 1.50-1.10 (m, 4H, CH₂); 1.01-0.82 (m, 4H, CH₂); 0.73 (t, 3H,J=7 Hz, CH₃); Minor isomer (distinguishable peaks in mixture with majorisomer) 7.24 (d, 1H, J=7.3 Hz, Ar--H); 7.15 (s, 2H, Ar--H); 5.18 (dd,1H, J=10.3 and 6.5 Hz, SCH); 3.90-3.72 (m, 1H, SCH ₂); 240 (s, 3H,Ar--H₃); 2.31 (s, 3H, Ar--H₃). ¹³ C-NMR: Major isomer 141.11; 137.96;132.27; 127.98; 127.84; 122.86; 63.09; 44.73; 38.92; 31.49; 27.59;26.61; 21.41; 21.34; 19.33; 13.16; Minor isomer (distinguishable peaksin mixture with major isomer) 139.75; 135.89; 128.24; 128.18; 127.54;65.89; 43.53; 43.28; 38.36; 28.79; 27.37; 21.41; 20.42; 13.16. IR: 1615;1466; 1451; 820; 658 cm⁻¹. Anal. Calcd for C₁₆ H₂₅ SSbF₆ : C, 39.61; H,5.19; S, 6.61. Found: C, 39.3; H, 5.2; S, 6.6.

Example 21

S-Butyl-2-(2-methyl,4-methoxyphenyl)tetrahydrothiopheniumhexafuorophosphate [1g(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 5.8 mL, 39 mmol) was added to a mixture of diol 6g(5.54 g, 26 mmol) and BuSH (3.9 mL, 36.4 mmol) kept at 0° C. and underN₂ -atmosphere. The temperature was raised to RT and the mixture wasstirred for 17 h. H₂ O (10 mL) and CH₂ Cl₂ (10 mL) was added, the layerswere separated and the aqueous-layer was extracted with CH₂ Cl₂ (2×20mL). The combined organic layers were washed with H₂ O (10 mL), aqueousNaHCO₃ (sat., 10 mL) and dried (MgSO₄). Evaporation gave 9.309 g (76%)of 1g(S-Bu)-PF₆ as a 1/1 mixture of diastereomers. Recrystallization inEtOH (45 mL) gave 4.43 g (42%) of 1g(S-Bu)-PF₆ as white crystals. ¹H-NMR: Major isomer 7.47 (s, 1H, Ar); 7.42 (s, 1H, Ar); 6.85-6.76 (m,1H, Ar); 5.39-5.29 (m, 1H, Ar--CH), 4.08-3.91 (m, 2H, CH₂); 3.82 (s, 3H,OCH₃); 3.5-3.4 (m, 2H, CH₂); 2.09-2.62 (m, 2H, CH₂); 2.44 (s, 3H, CH₃);1.80-1.20 (m, 6H, CH₂); 0.74 (t, 3H, J=7 Hz, CH₃); Minor isomer(distinguishable peaks in mixture with major isomer) 7.30 (s, 1H, Ar);7.27 (s, 1H, Ar); 5.25-5.15 (m, 1H, Ar--CH); 3.80 (s, 3H, OCH₃); 2.42(s, 3H, CH₃); 2.42 (2, 3H, CH₃); 0.91 (t, 3H, J=7 Hz, CH₃).

Example 22

S-Butyl-2-(2,4-dimethoxyphenyl)-tetrahydrothiophenium hexafuorophosphate[1 h(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 3.9 mL, 26.52 mmol) was added to a mixture of diol 6h (4 g, 17.68 mmol) and BuSH (2.7 mL, 24.75 mmol) kept at 0° C. andunder N₂ -atmosphere. The mixture turn red under the addition of HPF₆.The temperature was raised to RT and the reaction mixture was stirredfor 16 h. H₂ O (30 mL) and CH₂ Cl₂ (50 mL) was added, the layers weresepareted and the aqueous-layer was extracted with CH₂ Cl₂ (2×25 mL).The combined organic layers were was washed with H₂ O (30 mL), aqueousNaHCO₃ (sat., 2×25 mL) and dried (MgSO₄). Evaporation gave 4.96 g (66%)yellow oil of 1 h(S-Bu)-PF₆ as a 3.7/1 mixture of diastereomers. ¹H-NMR: Major isomer 7.4-7.15 (Ar--H); 6.55-6.45 (Ar--H); 5.02-4.92 (dd,1H, CH--S); 3.90 (s, 3H, OCH₃); 3.79 (s, 3H, OCH₃); 3.65-3.55 (m, 2H,CH₂); 3.30 (t, 2H, S--CH₂ CH₂ CH₂ CH₃); 2.80-2.40 (m, 4H, CH₂);1.85-1.65 (m, 4H, CH₂); 0.94 (t, 3H, J=7.3 Hz, CH₃); Minor isomer(distinguishable peaks in mixture with major isomer) 5.29-5.18 (dd, 1H,CH--S); 4.05-3.95 (t, 2H, S--CH₂ CH₂ CH₂ CH₃); 0.66 (t, 3H, J=7.3 Hz,CH₃).

Example 23

S-Butyl-2-(2,4,6-trimethylphenyl)-tetrahydro-thiopheniumhexafuorophosphate [1i(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 2.92 g, 12 mmol) was added slowly to a solution ofdiol 6i (1.25 g, 6 mmol) and BuSH (0.81 g, 9 mmol) in CH₂ Cl₂ (8 mL)kept at 0° C. The reaction mixture was stirred for 24 h. Workupaccording to general procedure A gave 1.46 g (59%) uellow oil of1i(S-Bu)-PF₆ as a >10/1 mixture of diastereomers. ¹ H-NMR: 6.91 (s, 2H,Ar--H); 5.44 (dd, 1H, CH--S); 3.98-3.35 (m, 4H, CH₂ --S); 2.9-2.2 (m,4H, CH--CH₂ CH₂); 2.43 (s, 6H, o-CH₃); 2.28 (s, 3H, p-CH₃); 1.73 (m, 2H,CH₂ --CH₂ --CH₃); 1.46 (sext, 2H, CH₂ --CH₃); 0.91 (t, 3H, CH₂ CH₃).

Example 24

S-Butyl-2-(2,6-dimethyl,4-methoxyphenyl)tetrahydrothiopheniumhexafuorophosphate [1j(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 4.9 mL, 33.44 mmol) was added to a mixture of diol 6j(5 g, 22.29 mmol) and BuSH (3.4 mL, 31.21 mmol) in CH₂ Cl₂ (5 mL) keptat 0°C. and under N₂ -atmosphere. The reaction mixture was stirred for 1h 45 min at 0° C. and for 3 h at RT. H₂ O (5 mL) was added and thelayers were separated. The aqueous-layer was extracted with CH₂ Cl₂ (2×5mL). The combined organic layers were washed with H₂ O (5 mL), aqueousNaHCO₃ (sat., 2×5 mL) and dried (MgSO₄). Evaporation gave 9.24 g (98%)of 1j(S-Bu)-PF₆. Recrystallization in EtOH gave 4.11 g (43%) whitecrystals of 1j(S-Bu)-PF₆ as a >10/1 mixture of diastereomers. 1H-NMR:6.69 (s, 1H, Ar); 6.64 (s, 1H, Ar); 5.09-5.01 (m, 1H, Ar--CH); 3.89 (s,3H, OCH₃); 3.65-3.61 (m, 2H, CH₂); 3.28-3.19 (m, 2H, CH₂); 2.73-2.65 (m,2H, CH₂); 2.39 (s, 3H, Ar--CH₃); 2.32 (s, 3H, Ar--CH₃); 1.80-1.65 (m,2H, CH₂); 1.55-1.40 (m, 2H, CH₂); 0.92 (t, 3H, J=7.2 Hz, CH₃). ¹³ C-NMR:140.9: 138.0; 132.2; 128.0; 127.8; 123.1; 62.8; 44.6; 38.7; 31.4; 27.4;26.5; 21.3; 21.0; 19.3; 13.0.

Example 25

S-Butyl-2-(4-methoxyphenyl)-pyranium hexafluorophosphate [1k(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 2.92 g, 12 mmol) was added slowly to a solution ofdiol 6k (0.63 g, 3 mmol) and BuSH (0.14 g, 4.5 mmol) in CH₂ Cl₂ (3 mL)kept at 0° C. The reaction mixture was stirred for 120 h. Workupaccording to the general procedure A gave 0.38 g (32%) brown oil of 1k(S-Bu)-PF₆ as a >10/1 mixture of diastereomers. ¹ H-NMR: 7.43 (d, 2H,Ar--H); 6.95 (d, 2H, Ar--H); 5.45 (brd, 1H, CH--S); 4.00-2.96 (m, 4H,CH₂ --S); 3.83 (s, 3H, CH₃₋₋ O); 2.6-0.9 (m, 10H, CH₂); 0.80 (t, 3H, CH₃--CH₂).

Example 26

S-Butyl-[3,4]-benzo-2,5-dihydrothiophenium hexafluorophosphate (3A)

Aqueous HPF₆ (60%, 3.8 mL, 25.97 mmol) was added to a mixture of diol12A (1 g, 7.42 mmol) and BuSH (1.6 mL, 14.48 mmol) kept at 0° C. andunder N₂ -atmosphere. The temperature was raised to RT and the reactionmixture was stirred for 66 h. H₂ O (10 mL) and CH₂ Cl₂ (50 mL) was addedand the layers were separated. The aqueous-layer was extracted with CH₂Cl₂ (20 mL). The combined organic layers were washed with aqueous NaHCO₃(sat., 10 mL) and dried (MgSO₄). Evaporation gave 1.41 g (56%) of 3A. ¹H-NMR 7.5-7.15 (m, 4H, Ar); 5.03 (d, 2H, J=17 Hz, CH₂ S); 4.60 (d,2H,J=17 Hz, CH₂ S); 3.16 (t, 2H, J=7HZ, S--CH₂); 1.8-1.6 (m, 2H, SCH₂CH₂); 1.6-1.25 (m, 2H, SCH₂ CH₂ CH₂); 0.92 (t, 3H, J=7 Hz, S(CH₂)₃ CH₃).¹³ C-NMR 133.18; 129.0; 125.93; 46.34; 39.94: 25.91; 21.44; 13.19 IR:3632: 2962; 2876; 1826; 1585; 1490; 1459; 1409; 1286; 1246; 1212; 1055;961; 916; 888; 753; 692; 521; 425.

Example 27

S-Butyl-2-phenyl-[3,4]-benzo-2,5-dihydro-thiophenium hexafluorophosphate(3B)

Aqueous HPF₆ (60%, 2.4 mL, 16.34 mmol) was added to a mixture of diol12B (1 g, 4.67 mmol) and BuSH (1 mL, 9.3 mmol) kept at 0° C. and underN₂ -atmosphere. After 30 minutes stirring, CH₂ Cl₂ (1.5 mL) was addedand the temperature was raised to RT. The reaction mixture was stirredfor 7 h. H₂ O (10 mL) and CH₂ Cl₂ (50 mL) was added and the layers wereseparated. The aqueous-layer was extracted with CH₂ Cl₂ (20 mL). Thecombined organic layers were washed with aqueous NaHCO₃ (sat., 15 mL)and dried (MgSO₄). Evaporation gave 1.385 g (69%) of 3B (containig 8% of3A) as a 2.2/1 mixture of diastereomers. ¹ H-NMR d=7.6-7.2 (m, 18H,Ar--H, major+minor); 7.05 (s, 1H, Ar--CH--S, minor); 6.49 (s, 1H,Ar--CH--S, major); 5.1 (d, 1H, J=17 Hz, CH₂ --S, minor); 5.0 (d, 2H,J=17 Hz, CH₂ --S, major); 4.83 (d, 2H, J=17 Hz, CH₂ --S, major); 4.74(d, 2H, J=17 Hz, CH₂ --S, minor); 3.65-3.5 (m, 1H, S--CH₂, major);3.4-3.3 (m, 2H, S--CH₂, major); 2.95-2.8 (m, 1H S--CH₂, minor); 2.65-2.5(m, 1H, S--CH₂, minor); 1.9-1.7 (m, 4H, SCH₂ --CH₂, major+minor);1.5-1.3 (m, 4H, SCH₂ CH₂ --CH₂, major+minor); 0.91 (t, 3H, J=7 Hz.S(CH₂)₃ CH₃, major); 0.68 (t, 3H, J=7 Hz, S(CH₂)₃ CH₃, minor). IR: 2963;2875; 2360; 1488; 1456; 1414; 1287; 1055; 753; 706; 601; 522; 430.

Example 28

S-Butyl-2-iso-propyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate (3C)

Aqueous HPF₆ (60%, 1.15 mL, 7.8 mmol) was added to a mixture of diol 12C(0.4 g, 2.23 mmol) and BuSH (0.5 mL, 4.46 mmol) kept at 0° C. and underN₂ -atmosphere. The temperature was raised to RT and the reactionmixture was stirred for 6 h. H₂ O (6 mL) and CH₂ Cl₂ (30 mL) was addedand the layers were separated. The aqueous-layer was extracted with CH₂Cl₂ (10 mL). The combined organic layers were washed with aqueous NaHCO₃(sat., 10 mL) and dried (MgSO₄). Evaporation gave 0.37 g (38%) of 3C asa 3.3/1 mixture of diastereomers. ¹ H-NMR 7.53-7.4 (m, 8H, Ar,major+minor); 5.46 (d, 1H, J=7 Hz, (CH₃)₂ CHCH, minor), 4.93 (s, 1H,(CH₃)₂ CHCH, major); 4.90 (d, 1H, J=17 Hz, CH₂ --S, minor); 4.90 (d, 1H,J=17 Hz, CH₂ --S, major); 4.75 (d, 1H, J=17 Hz, CH₂ --S, major); 4.58(d, 1H, J=17 Hz, CH₂ --S, minor); 3.45-3.1, 3-2.85, 2.7-2.45 (m, 6H,SCH₂, major+minor samt (CH₃)₂ CH, major+minor); 1.88-1.73 (m, 4H, SCH₂CH₂, major+minor); 1.61-1.46 (m, 4H, SCH₂ CH₂ CH₂, major+minor); 1.35(d, 3H,J=7 Hz, CH₃, minor); 1.33 (d, 3H,J=7 Hz, CH₃, minor); 1.26 (d,3H,J=7 Hz, CH₃, major); 0.98 (d, 3H, J=7 Hz, CH₃, major); 0.97 (t, 3H,J=7 Hz, S(CH₂)₃ CH₃, major); 0.93 (t, 3H, J=7 Hz, S(CH₂)₃ CH₃, minor).¹³ C-NMR 130; 129.5; 126.1; 73.2; 46.2; 41.3; 33.8; 26.3; 21.5; 20.7;18.1; 13.3. IR: 3636; 2965; 2877; 1631; 1468; 1417; 1394; 1374; 1286;1056; 759; 522; 440.

Example 29

S-Butyl-2,2-dimethyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate (3D)

Aqueous HPF₆ (60%, 3 mL, 21 mmol) was added to a mixture of diol 12D (1g, 6 mmol) and BuSH (1.3 mL, 12 mmol) kept at 0° C. and under N₂-atmosphere. The reaction mixture was stirred for 1 hour at 0° C. andfor 49 h at RT. H₂ O (10 mL) and CH₂ Cl₂ (10 mL) was added and thelayers were separated. The aqueous-layer was extracted with CH₂ Cl₂(3×10 mL). The combined organic layers were washed with aqueous NaHCO₃(sat., 10 mL) and dried (MgSO₄). Evaporation and extractions withpetroleumether gave 1.1 g (43%) of 3D as yellow crystals. ¹ H-NMR7.55-7.4 and 7.3-7.05 (m, 4H, Ar--H); 5.04 (d, 1H, J=16 Hz, CH₂ --S);4.7 (d, 1H, J=17 Hz, CH₂ --S); 3.42-3.25 (m, 1H, S--CH₂); 3.08-2.9 (m,1H, S--CH₂); 2.03 (s, 3H, CH₃); 1.88 (m, 3H, CH₃); 1.9-1.7 (m, 2H, SCH₂--CH₂); 1.6-1.4 (m, 2H, SCH₂ CH₂ CH₂); 0.94 (t, 3H, J=7 Hz, S(CH₂)₃CH₃). ¹³ HC-NMR 142.4; 132.2; 129,9; 126.6; 123.1; 71.6; 42.3; 36.9;29.3; 26.6; 22.4; 21.8; 13.3. IR: 2971; 2878; 1485; 1468; 1456; 1410;1376; 1103; 838; 766; 735; 558; 437.

Example 30

S-Butyl-2-metyl-2-phenyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate (3E)

Aqueous HPF₆ (60%, 3 mL, 21 mmol) was added to a mixture of diol 12E(600 mg, 2.63 mmol) and BuSH (1.3 mL, 12 mmol) kept at 0° C. and underN₂ -atmosphere. The temperature was raised to RT and the reactionmixture was stirred for 4.5 h. H₂ O (10 mL) and CH₂ Cl₂ (10 mL) wasadded and the layers were separated. The aqueous-layer was extractedwith CH₂ Cl₂ (3×10 mL). The combined organic layers were washed withaqueous NaHCO₃ (sat., 10 mL) and dried (MgSO₄). Evaporation gave 1.135 g(73%) of 3E, ¹ H-NMR 7.55-7.4 and 7.3-7.05 (m, 4H, Ar--H); 5.04 8d, 1HJ=16 Hz, CH₂ --S); 4.7 (d, 1H, J=17 Hz, CH₂ --S); 3.42-3.25 (m, 1H,S--CH₂); 3.08-2.9 (m, 1H, S-CH₂); 2.03 (s, 3H, CH₃); 1.88 (s, 3H, CH₃);1.9-1.7 (m, 2H, S--CH₂ --CH₂); 1.6-1.4 (m, 2H, S--CH₂ --CH₂); 0.94 (t,3H, J=7 Hz, S--(CH₂)₃ CH₃). ¹³ C-NMR 139.7; 137.5; 134.5; 130.6; 130.1;129.5; 127.64; 127.4; 125.6; 78.3; 41.4; 37.1; 26.5; 22.9; 21.9; 13.4.IR: 2946; 2878; 1493; 1456; 1407; 1392; 1289; 1215; 1191; 1061; 782;762; 737; 703; 650; 613; 561; 522.

Example 31

S-Butyl-2,2-diphenyl-[3,4]-benzo-2,5-dihydrothiopheniumhexafluorophosphate (3F)

Aqueous HPF₆ (60%, 1.8 mL, 12 mmol) was added to a mixture of diol 12F(1 g, 3.44 mmol) and BuSH (0.74 mL, 6.9 mmol) kept at 0° C. and under N₂-atmosphere. After 1 hours stirring at 0° C., CH₂ Cl₂ (0.5 mL) was addedand the reaction mixture was stirred for 21 h at RT. H₂ O (6 mL) and CH₂Cl₂ (30 mL) was added and the layers were separated. The aqueous-layerwas extracted with CH₂ Cl₂ (10 mL). The combined organic layers werewashed with aqueous NaHCO₃ (sat., 6 mL) and dried (MgSO₄). Evaporationgave 1.208 g (60%) of 3F. ¹ H-NMR 7.6-7.35 (m, 14H, Ar--H); 5.02 (s, 2H,CH₂ --S); 3.25-3.1 (m, 1H, S--CH ₂); 2.7-2.5 (m, 1H, S--CH₂); 1.6-1.35(m, 2H, SCH₂ CH₂); 1.35-1.1 (m, 2H, SCH₂ CH₂ CH₂); 0.7 (t, 3H, J=7 Hz,S(CH₂)₃ CH₃). ¹³ C-NMR 131.1; 130.5; 1.35; 130.3; 129.6; 129.4; 127.4;127.6; 127.2; 45.8; 40.1; 26.3; 21.67; 13.0. IR=3436; 2964; 1495; 1451;1410; 1285; 1241; 1056; 769; 757; 744; 698; 634; 623; 521; 437.

Example 32

S-Butyl-5-methyl-[3,4]-benzo-2,7-dihydrothiephinium hexafluorophosphate(5A)

The diol 12G (50 mg, 0.281 mmol) was added to a mixture of aqueous HPF₆(60%, 144 μL, 0.98 mmol), BuSH (60 μL, 0.56 mmol) and CH₂ Cl₂ (500 μL)kept at 0° C. The reaction mixture was stirred for 6 h at RT. H₂ O andCH₂ Cl₂ was added and the layers were separated. The aqueous-layer wasextracted with CH₂ Cl₂ and the combined organic layers were washed withaqueous NaHCO₃ (sat.) and dried (MgSO₄). Evaporation and extractionswith petroleumether gave 50 mg (47%) of 5A. ¹ H-NMR 7.6-7.3 (m, 4HAr--H); 6.1 (t, 1H, C═CH) 4.45 (d, 1H, J=13 Hz, ArCH₂ S); 4.16 (d, 1H,J=13 Hz, ArCH₂ S); 3.75-3.62 (m, 1 H, SCH₂), 3.45-3.15 (m, 3H, SCH₂+C═CHCH₂ S); 1.88-1.72 (m, 2H, SCH₂ CH₂); 1.6-1.4 (m, 2H, SCH₂ CH₂ CH₂);0.95 (t, 3H, J=7 Hz, S(CH₂)₃ CH₃). ¹³ C-NMR 148.5; 141.1; 131.5; 130.7;129.1; 127.8; 125.6; 114.7; 39.2; 38.7; 35.2; 25.9; 23; 21.6; 13.1. IR:3629; 2963; 2875; 1636; 1490; 1424; 1285; 1056; 769; 521.

Example 33

S-Butyl-5-phenyl-[3,4]-benzo-2,7-dihydrothiephinium hexafluorophosphate(5B)

Aqueous HPF₆ (60%, 2.4 mL, 16.34 mmol) was added to a mixture of diol12I (1 g, 4.67 mmol) and BuSH (1 mL, 9.3 mmol) kept at 0° C. and underN₂ -atmosphere. After 30 minutes stirring at RT CH₂ Cl₂ (1.5 mL) wasadded. The reaction mixture was stirred for 6 more h. H₂ O (10 mL) andCH₂ Cl₂ (50 mL) was added and the layers were separated. Theaqueous-layer was extracted with CH₂ Cl₂ (20 mL). The combined organiclayers were washed with aqueous NaHCO₃ (sat., 15 mL) and dried (MgSO₄).Evaporation gave 1.385 g (60%) of 5B. ¹ H-NMR 7.65-7.15 (m, 9H, Ar--H);6.52-(t, 1H, J=7 Hz, C═CH); 4.54 (d, 1H, J=14 Hz, ArCH.sub. 2 S); 4.21(d, 1H, J=14 Hz, ArCH₂ S); 3.48-3.18 (m, 3H, SCH₂ and C═CHCH₂ S);1.92-1.73 (m, 2H, SCH₂ CH₂); 1.63-1.41 (m, 2H, SCH₂ CH₂ CH₂); 0.96 (t,3H, J=7 Hz, S(CH₂)₃ CH₃). ¹³ C-NMR 151.3; 139.6; 138.5; 131.7; 131;129.9; 129.6; 128.7; 128.2; 127.4; 114.7; 39.6; 39.2; 21.8; 13.3. IR:3414; 2961; 1617; 1447; 1059; 766; 700; 634; 522.

Example 34

S-Butyl-isothiochromanium hexafluorophosphate [4a(S-Bu)-PF₆ ]

Aqueous HPF₆ (60%, 7.30 g, 30 mmol) was added slowly to a mixture ofisochromanone (13) (2.68 g, 20 mmol) and BuSH (1.80 g, 20 mmol). Thereaction mixture was stirred for 1 week at RT and for 2 days at 50° C.H₂ O (10 mL) was added and the layers were separated. The aqueous-layerwas extracted with CH₂ Cl₂ (2×20 mL). The combined organic layers werewashed with aqueous NaHCO₃ (sat., 2×10 mL) and dried (MgSO₄).Evaporation gave 5.95 g (85%) of 4a(S-Bu)-PF₆.¹ H-NMR: 7.53-7.10 (m, 4H,Ar--H); 4.44 (dd, 2H, ArCH₂ S); 4.08-2.80 (m, 6H, CH₂); 1.73 (m, 2H, CH₂CH₂ S); 1.46 (m, 2H, CH₂ CH₃); 0.92 (t, 3H, CH₃). ¹³ C-NMR (DMSO-D₆):135.64; 129.57; 129.34; 128.97; 127.62; 126.55; 39.57; 35.65; 35.31;25.27; 25.10; 20.96; 13.14.

Example 35

S-Benzyltetrahydrothiophenium hexafluorophosphate (2)

Aqueous HPF₆ (60%, 13.99 g, 57.5 mmol) was added to a mixture of THF(2.07 g, 28.55 mmol) and benzylmercaptan (5 g, 28 mmol). The reactionmixture was stirred for 21 h. H₂ O (13 mL) and CH₂ Cl₂ (13 mL) was addedand the layers were separated. The aqueous-layer was extracted with CH₂Cl₂ (2×20 mL). The combined organic layers were washed with H₂ O (20mL), aqueous NaHCO₃ (sat., 2×20 mL) and dried (MgSO₄). Evaporation gave3.633 (40%) of 2. ¹ H-NMR (aceton-d₆): 7.67-7.63 (m, 2H, Ar--H₂);7.52-7.50 (m, 3H, Ar--H); 4.76 (s, 2H, ArCH₂ S); 3.75-3.66 (m, 2H, CH₂);2.51-2.41 (m, 2H, CH₂). ¹³ C-NMR (aceton-d₆ ): 131.31 (2C); 130.75;130.46 (2C); 46.58; 43.55;

Example 36

Kinetic study of formation ofS-Butyl-2-(2,4-dimethylphenyl)-tetrahydrothiophenium hexafluorophosphate[1f(S-Bu)-PF₆ ]

Aqueous HPF₆ (31%, 1.5 eq) was added to a mixture of diol 6f (1 eq) andBuSH (1 eq). The reaction mixture was stirred at 25° C. and monitored by¹ H-NMR analysis. Samples of 0.2 mL were diluted with CDCl₃ (1 mL) andneutralized with K₂ CO₃ followed by filtration through cotton. Cyclicether 7f:¹ H-NMR: 7.32 (d, 1H, Ar--H); 7.00 (d, 1H, Ar--H); 6.95 (s, 1H,Ar--H); 5.05 (t, 1H, J=7.0 Hz, CH--O); 4.13 (q, 1H, CH₂ --O); 3.92(q,1H, CH₂); 2.42-2.24 (m, 1H, CH₂); 2.30 (s, 1H, CH₃ --Ar); 2.27 (s,1H, CH₃ --Ar); 1.99 (quint, 2H, CH₂ CH); 1.76-1.57 (m, 1H, CH₂). Sulfidoalcohol, 8f(S-Bu): ¹ H-NMR: 7.31 (d, 1H, Ar--H); 6.99 (d, 1H, Ar--H);6.94 (s, 1H, Ar--H); 4.05 (t, 1H, J=7.5 Hz, CH--S); 3.58 (t, 2H, J=6.4Hz, CH₂ --O); 2.31 (s, 3H, CH₃ --Ar); 2.28 (s, 3H, CH₃ --Ar); 2.0-1.8(m, 2H, CH₂); 1.7-1.2 (m, 4H, CH₂); 0.83 (t, 3H, CH₃).

Example 37

Transformation of the diol 6c to the cyclic ether 7c

To a ether solution (50 mL) of the diol 6c (2.94 g, 15 mmol) was addedconcentrated sulfuric acid (4 drops, 80 mg). The reaction mixture wasstirred an 25° C. for 2 h. Saturated NaHCO₃ (aqueous 2 mL) was added andthe organic phase was collected, dried and concentrated to yield 2.6 g(97%) of 7c as a colorless liquid. ¹ H-NMR: 7.26 (d, 2H, J=8.6, Ar--H);6.87 (d, 2H, J=8.7, Ar--H); 4.87 (t, 1H, J=7.0, CH--S); 4.20-3.89 (m,2H, CH₂ S), 3.84 (s, 3H, MeO), 2.40-1.77 (m, 4H, C--CH₂ --CH₂ --C).

Example 38

Synthesis ofS,S'-ethylene-1,2-bis[2-(4-methoxyphenyl)tetrahydrothiopheniumhexafluorophospate]1c(S,S'-ethylene)-PF₆

To a mixture of cyclic ether 7c (712 mg, 4 mmol) and1,2-dimercaptoethane (188 mg, 2 mmol) was slowly added aqueous HPF6 (1.1mL, 60% w/w, 8 mmol). After stirring for 1 h at 25° C. water (2 mL) wasadded and the slurry was filtrated. The crystals were washed with waterand aqueous NaHCO₃ and dried yielding 1.40 g (99%) of1c(S,S'-ethylene)-PF₆ as yellow crystals. mp=118°-122° C. ¹ H-NMR(acetone-d₆) 7.6-7.0 (m, 4H, Ar--H); 5.9-5.3 (m, 1H, CH--S); 4.4-3.7(8H, including MeO); 3.0-2.4 (m, 4H). Anal. Calcd for C₂₄ H₃₂ S₂ P₂ F₁₂: C, 40.8; H, 4.56; S, 9.10; P, 8.7. Found: C, 40.3; H, 4.6; S, 9.2; P,8.3.

Example 39

Synthesis ofS,S'-hexylene-1,6-bis[2-(4-methoxyphenyl)tetrahydrothiopheniumhexafluorophospate] [1c(S,S'-hexylene)-PF₆ ]HPF₆ (1.47 mL, 10 mmol) wasadded to a solution of THF-derivative 7c (890 mg, 5 mmol) and1,6-dimercaptohexane (375 mg, 2.5 mmol). The reaction mixture wasstirred for 2 h at 25° C. Water (3 mL) was added and the reactionmixture was extracted with CH₂ Cl₂ (3×2 mL) and the combined organiclayers were washed with aqueous NaHCO₃ (sat., 2×1 mL). Drying with MgSO₄and evaporation gave the disalt as white crystals, 1.9 g (83%).mp=56°-62° C. ¹ H-NMR(aceton-d₆): 7.64-7.50 (m, 2H, Ar--H); 7.12-6.96(m, 2H, Ar--H); 5.69-5.57 (m, 0.5 H, CH--S); 5.40-5.22 (m, 0.5H, CH--S);4.18- 3.48 (m, 14H, CH₂ --S and); 3.90-3.48 (m, CH₂ --S and OCH₃);3.20-1.05 (m,16H, --CH₂ --).

Example 40

Synthesis ofS,S'-p-xylylene-bis[2-(4-methoxyphenyl)tetrahydrothiopheniumhexafluorophospate][1c(S,S'-p-xylylene)-PF₆ ]

HPF₆ (0.5 mL, 3.5 mmol) was added to a solution of cyclic ether 7c (155mg, 0.87 mmol) and p-xylene-α,α'-dithiol (74 mg, 0.43 mmol). Thereaction mixture was stirred for 4 h at 25° C. Water (3 mL) was addedand the slurry was filtrated. The crystals were washed with NaHCO₃ (aq)and dried to yield 280 mg (86%) of 1c(S,S'-p-xylylene)-PF₆ as yellowcrystals. mp=96°-103° C.1H-NMR(acetone-d₆): 7.80-6.74 (m, 12H, Ar--H);5.82-5.66 and 5.50-5.30 (m, 2H, CH--S); 5.07 and 5.01 (two s, benzylic);4.59-3.52 (m, 10H, CH₂ --S and CH₃ O); 3.00-2.33 (m, 8H, CH₂ --).

Example 41

Synthesis of 1c(S-Bu)-PF₆ by addition of diol/ether toacid/mercaptan-mixture

Cyclic ether 7c (155 mg, 0.87 mmol) was added dropwise to a mixture ofHPF₆ (0.25 mL, 1.74 mmol) and BuSH (79 mg, 0.87 mmol) and the reactionmixture was stirred for 4 h at 25° C. Workup according to the generalprocedure A yielded 254 mg (95%) of 1c(S-Bu)-PF₆ as white crystals.

General procedure for the synthesis of ketoacids (11)

AlCl₃ (95%, 2 eq) was added to an ice-cooled slurry of succinicanhydride (99%, 1 eq) in the aromatic compound 10 (4.3-6 eq). Thereaction mixture was stirred at RT for the indicated time and thancooled with ice. HCl (2M) was added in small portions. The resultingcrude product was filtrated and dried. For most cases the crude productwas used in the proceeding step. The acids was in some cases purified bythe following procedure: the crystals were dissolved in NaOH (2M) andthe solution was extracted with diethylether. The aqueous phase wasacidified with HCl (conc.) to pH<1 and the acid pricipitates. Thecrystals were filtrated, washed with HCl (2M) and H₂ O and dried to give11.

3-(4-Methylbenzoyl)-propionic acid (11b)

Toluene 10b (99.9%, 5.5 eq) was reacted with succinic anhydride (99%, 1eq) and AlCl₃ (95%, 2 eq) for 24 h according to the general procedure.Yellow crystals of 11b were obtained in 75% yield. ¹ H-NMR: 7.88 (d, 2H,J=8.2 Hz, Ar--H); 7.26 (d, 2H, J=4.8 Hz, Ar--H); 3.29 (t, 2H, J=6.6 Hz,CH₂ CH₂ COOH); 2.80 (t, 2H, J=6.6 Hz, CH₂ CH₂ COOH); 2.41 (s, 3H, CH₃).¹³ C-NMR: 192.44; 178.70; 144.13; 133.91; 129.29; 128.14; 33.02; 28.06;21.63.

3-(4-Methoxybenzoyl)-propionic acid (11c)

Anisole 10c (4 L, 99%, 37 mol) was reacted with succinic anhydride (670g, 99%, 6.7 mol) and AlCl₃ (1.88 kg, 95%, 14.1 mol) for 20 h accordingto the general procedure. Fluid bed drying of the crude product afforded1.0 kg (72%) yellowish crystals of 11c. ¹ H-NMR: 7.97 (d, 2H, J=8.9 Hz,Ar--H); 6.94 (d, 2H, J=8.9 Hz, Ar--H); 3.87 (s, 3H, OCH₃); 3.27 (t, 2H,J=6.7 Hz; CH₂ CH₂ COOH); ¹³ C-NMR (CDCl₃ +DMSO-d₆): 196.22; 174.29;162.95; 129.68 (2C); 129.21; 113.19 (2C); 54.95; 32.67; 27.70. IR (KBr):2973; 1702; 1655; 1598; 1486; 1439; 1289; 1260; 1246; 757 cm⁻¹.

3-(4-iso-Propylbenzoyl)-propionic acid (11d)

Cumene 10d (99%, 4.8eq) was reacted with succinic anhydride (99%, 1 eq)and AlCl₃ (95%, 2 eq) for 120 h according to the general procedure.Extractive purification of the crude product afforded white crystals of11d were obtained in 83% yield. ¹ H-NMR: 7.92 (d, 2H, Ar--H); 7.32 (d,2H, Ar--H); 3.30 (t, 2H, CH₂ CH₂ COOH); 2.97 (sept., 1H,CH(CH₃)₂); 2.81(t, 2H, CH₂ CH₂ COOH); 1.27 (d, 6H, CH(CH₃)₂).

3-(4-tert-Butylbenzoyl)-propionic acid (11e)

tert-Butylbenzene 10e (99%, 4.3 eq) was reacted with succinic anhydride(99%, 1 eq) and AlCl₃ (95%, 2 eq) for 120 h according to the generalprocedure. Extractive purification of the crude product afforded whitecrystals of 11e in 68% yield. ¹ H-NMR: 7.93 (d, 2H Ar--H); 7.48 (d, 2H,Ar--H); 3.30 (t, 2H, CH₂ CH₂ COOH); 2.81 (t, 2H, CH₂ CH₂ COOH); 1.34 (s,9H, CH₃).

3-(2,4-Dimethylbenzoyl)-propionic acid (11f)

m-Xylene 10f (98%, 5.5 eq) was reacted with succinic anhydride (99%, 1eq) and AlCl₃ (95%, 2 eq) for 42 h according to the general procedure.Extractive purification of the crude product afforded white crystals of11f were obtained in 92% yield. ¹ H-NMR: 7.66 (d, 1H, Ar--H); 7.07 (d,2H, Ar--H); 3.22 (t, 2H, CH₂ CH₂ COOH); 2.77 (CH₂ CH₂ COOH); 2.49 (s,3H, CH₃); 2.35 (s, 3H, CH₃).

3-(2-Methyl-4-methoxybenzoyl)-propionic acid (11g)

3-Methylanisole 10g (99%, 6 eq) was reacted with succinic anhydride(99%, 1 eq) and AlCl₃ (95%, 2 eq) for 20 h according to the generalprocedure. White crystals of 2 isomers were obtained:3-(2-methyl-4-methoxybenzoyl)-propionic acid (53%) and3-(2-methoxy-4-methylbenzoyl)-propionic acid (27%). The crude productwas recrystallized in EtOH to give pureβ-(2-methyl-4-methoxybenzoyl)-propionic acid (11g) in 24% yield. ¹H-NMR: 7.80 (d, 1H, J=9.4 Hz; Ar--H); 6.79-6.75 (m, 2H, Ar--H); 3.85 (s,3H, OCH₃); 3.24 (t, 2H, J=6.3 Hz, CH₂ CH₂ COOH); 2.77 (t, 2H, J=6.3 Hz,CH₂ CH₂ COOH); 2.25 (s, 3H, CH₃). ¹³ C-NMR: 199.16; 178.33; 162.04;142.35; 131.67; 117.54; 110.67; 110.62; 55.30; 35.02; 28.39; 22.47.

3-(2,4-Dimethoxybenzoyl)-propionic acid (11 h)

1,3-Dimethoxybenzene 10 h (99%, 6 eq) was reacted with succinicanhydride (99%, 1 eq) and AlCl₃ (95%, 2 eq) for 19 h according to thegeneral procedure. Recrystallization in EtOH gave white crystals of 11 hin 68% yield. ¹ H-NMR: 7.89 (d, 1H, J=8.7 Hz, Ar--H; 6.55 (dd, 1H, J=8.7and 2.3 Hz, Ar--H); 6.46 (d, 1H, J=2.3 Hz, Ar--H); 3.91 (s, 3H, OCH₃);3.86 (s, 3H, OCH₃); 3.30 (t, 2H, J=6.6 Hz, CH₂ CH₂ COOH); 2.73(t, 2H,J=6.6 Hz, CH₂ CH₂ COOH). ¹³ C-NMR: 197.62; 164.79; 161.23; 132.96;105.29; 98.31; 55.54; 55.47; 38.42; 28.67.

3-(2,4,6-Trimethylbenzoyl)-propionic acid (11i)

Mesitylene 10i (99%, 4.8 eq) was reacted with succinic anhydride (99%, 1eq) and AlCl₃ (95%, 2 eq) for 72 h according to the general procedure.Extractive purification of the crude product afforded white crystals of11i in 54% yield. ¹ H-NMR (DMSO-d₆): 6.63 (s, 2H, Ar--H); 2.84 (t, 2H,CH₂ CH₂ COOH); 2.22 (s, 3H, p-CH₃); 2.18 (t, 2H, CH₂ CH₂ COOH); 2.13 (s,6H, o-CH₃).

-(2,6-Dimethyl-4-methoxybenzoyl)-propionic acid (11j)

3,5-Dimethylanisol 10j (99%, 6 eq) was reacted with succinic anhydride(99%, 1 eq) and AlCl₃ (95%, 2 eq) for 20 h according to the generalprocedure. Extractive purification of the crude product afforded whitecrystals of 11j in 93% yield. ¹ H-NMR: 6.63 (s, 1H, Ar--H); 6.56 (s, 1H,Ar--H); 3.79 (s, 3H, OCH₃); 3.11 (t, 2H, J=6.7 Hz, CH₂ CH₂ COOH); 2.75(t, 2H, J=6.7 Hz, CH₂ CH₂ COOH); 2.32 (s, 3H, CH₃); 2.19 (s,, 3H, CH₃).¹³ C-NMR: 205.32; 178.97; 156.41; 140.41; 136.05; 127.36; 123.73;109.01; 55.41; 38.84; 28.04; 21.49; 18.85.

3-(4-Methoxybenzoyl)-butanoic acid (11k)

Anisole 10k (99%, 6.1 eq) was reacted with glutaric anhydride (98%, 1eq) and AlCl₃ (95%, 2 eq) for 120 h according to the general procedure.Extractive purification of the crude product afforded 66% of 11k as ablack oil. ¹ H-NMR (Aceton-d₆): 7.99 (d, 2H, Ar--H); 7.02 (d, 2H,Ar--H); 3.89 (s, 3H, CH₃); 3.06 (t, 2H, CH₂ CO); 2.42 (t, 2H, CH₂ COOH);1.97 (quint, 2H, CH₂ COOH).

General procedure for the synthesis of 1-Aryl-1,4-butandiols (6)

The ketoacid, 11 (1 eq, as crystals or dissolved in THF) was addedslowly to an ice-cooled slurry of LiAlH₄ (1.3 eq, 5.2 eq hydride) in THF(1.5-2 mL/mmol ketoacid) under a N₂ -atmosphere. The reaction mixturewas stirred for 24 h at RT and then cooled with ice. Water (1 mL/gLiAlH₄) was added, followed by aqueous NaOH (15% w/w, 1 mL/g LiAlH₄)andH₂ O (3 mL/g LiAlH₄). CH₂ Cl₂ (2-3 mL/mmol ketoacid) and MgSO₄ (5-6spoons) was added. The slurry was filtrated with a glass filter funneland the precitate was washed with CH₂ Cl₂ (3 times). The filtrate wasevaporated to give the diol 6.

1-Phenyl-butane-1,4-diol (6a)

3-Benzoylpropionic acid 11a dissolved in THF was reacted with LiAlH₄according to the general procedure. The following workup procedure wasused: H₂ O was added and THF was evaporated. Diethylether and HCl (2M)was added. The aqueous layer was extracted with diethylether and thecombined organic layers were washed with H₂ O, aqueous NaHCO₃(saturated) and H₂ O. Drying (MgSO₄), filtration and evaporation gave80% yield of 6a. ¹ H-NMR: 7.35-7.22 (m, 5H, Ar--H); 4.70 (t, 1H,CH--OH); 3.64 (t, 2H, CH₂ OH); 3.10 (brs, 1H, CH--OH); 2.60 (brs, 1H,CH₂ --OH); 1.84 (q, 2H, CH₂ --CHOH); 1.72-1.61 (m, 2H, CH₂ CH₂ OH).

1-(4-Methylphenyl)-butane-1,4-diol (6b)

The acid 11b was reduced according to the general procedure.Recrystallization in petroleumether/EtOAc afforded 6b 70% yield. ¹H-NMR: 7.29-7.10 (m, 4H, Ar--H); 4.61 (t, 1H, J=6.1 Hz, Ar--CH--OH);3.63-3.55 (m, 2H, ArCH--CH₂); 3.52 (brs, 2H, OH); 2.32 (s, 3H, Ar--CH₃);1.77 (t, 2H, J=6.5 Hz, CH₆ CH₂ OH); 1.64-1.56 (m, 2H, CH₂ CH₂ CH₂ OH).¹³ C-NMR: 141.67; 136.98; 129.00 (2C); 125.71 (2C); 74.06; 62.62; 36.15;29.12; 21.03.

1-(4-Methoxyphenyl)-butane-1,4-diol (6c)

The acid 11c was reduced according to the general procedure andyellowish crystals of 6c were obtained in 63% yield. ¹ H-NMR: 7.28-7.24(m, 2H, Ar--H); 6.89-6.84 (m, 2H, Ar--H); 4.65 (t, 1H, J=6.2 Hz,Ar--CH--OH); 3.79 (s, 3H, ArOCH₃); 3.67-3.62 (m, 2H, CH₂); 2.90 (brs,OH); 2.60 (brs, OH); 1.91-1.80 (m, 2H, CH₂); 1.75-1.60 (m, 2H, CH₂).

1-(4-iso-Propylphenyl)-butane-1,4-diol (6d)

The acid 11d was reduced according to the general procedure and 6d wasobtained in 84% yield as a colorless oil. 1H-NMR: 7.21 (q, 4H, Ar--H.);4.64 (t, 1H, Ar--CH--OH); 3.60 (m, 2H, CH₂ --OH); 3.3 (brs, 1H, OH); 3.1(brs, 1H, OH); 2.90 (sept., 1H, CH--(CH₃)₂); 1.81 (q, 2H, CH--CH₂); 1.63(m, 2H, CH₂ CH₂ OH); 1.23 (d, 6H, CH₃).

1-(4-tert-Butylphenyl)-butane-1,4-diol (6e)

The acid 11e was reduced according to the general procedure and 6e wasobtained in 92% yield white crystals. ¹ H-NMR: 7.32 (dd, 4H, Ar--H);4.70 (t, 1H, Ar--CH--OH); 3.68 (t, 2H, CH₂ --OH); 2.6 (brs, 1H, OH); 2.2(brs, 1H, OH); 1.85 (q, 2H, CHCH₂); 1.67 (m, 2H) CH₂ CH₂ OH); 1.31 (s,9H, CH₃).

1-(2,4-Dimethylphenyl)-butane-1,4-diol (6f)

The acid 11f was reduced according to the general procedure and 6f wasobtained in 94% yield. ¹ H-NMR: 7.34 (d, 1H, Ar--H); 7.02 (d, 1H,Ar--H); 6.94 (s, 1H, Ar--H); 4.90 (dd, 1H, CH); 3.75-3.55 (m, 2H, CH₂OH); 2.8 (brs, 2H, OH); 2.29 (s, 3H, CH₃); 2.28 (s, 3H, CH₃); 1.86-1.60(m, 4H, CHCH₂ CH₂).

1-(2-Methyl-4-methoxyphenyl)-butane-1,4-diol (6g)

The acid 11g was reduced according to the general procedure and 6g wasobtained in 86% yield as yellowish crystals. ¹ H-NMR: 7.37 (d, 1H, J=8.5Hz, Ar--H); 6.76 (dd, 1H, J=8.5 and 2.5 Hz, Ar--H); 6.68 (d, 1H, J=2.5Hz, Ar--H); 4.91 (t, 1H, Ar--CH(OH)); 3.79 (s, 3H, OCH₃); 3.55-3.45 (m,2H, CH₂ --OH); 2.32 (s, 3H, CH₃); 1.85-1.65 (m, 4H, CH₂ CH₂). ¹³ C-NMR126.42; 115.93; 111.33; 70.47; 62.96; 55.18; 35.14; 29.56; 19.24.

1-(2,4-Dimethoxyphenyl)-butane-1,4-diol (6 h)

The acid 11 h was reduced according to the general procedure and whitecrystals of 6 h were obtained in 85% yield. ¹ H-NMR: 7.23 (d, 1H, J=9Hz, Ar--H); 6.51-6.46 (m, 2H, Ar--H); 4.88 (t, 1H, J=6 Hz, Ar--CH₂--OH); 3.83 (s, 3H, OCH₃); 3.81 (s, 3H, OCH₃); 3.70 (t, 2H, J=5.7 Hz,CH₂ --CH₂ --OH); 1.93-1.80 (m, 2H, CH₂ --CH₂ --OH); 1.78-1.63 (m, 2H,Ar--CH(OH)--CH₂). ¹³ C-NMR: 159.69; 157.10; 127.06; 125.02; 103.91;98.28; 69.24; 62.50; 55.12; 55.06; 34.15; 29.23.

1-(2,4,6-Trimethylphenyl)-butane-1,4-diol (6i)

The acid 11i was reduced according to the general procedure. The crude6i was obtained in 85% yield. Recrystallization in EtOAc/petroleumether(40/60) gave 6i in 52% yield as white crystals. ¹ H-NMR: 6.80 (s, 2H,Ar--H); 5.11 (dd, 1H, CH); 3.66 (q, 2H, CH₂ OH); 2.7 (brs, 2H, OH);2.2-1.6 (m, 4H, CHCH₂ CH₂).

1-(2,6-Dimethyl-4-methoxyphenyl)-butane-1,4-diol (6j)

The acid 11j was reduced according to the general procedure and whitecrystals of 6j were obtained in 77% yield. ¹ H-NMR: 6.59 (s,2H, Ar--H);4.87-4.78 (m, 1H, Ar--CH--OH); 3.84 (s, 3H, OCH₃); 3.62 (t, 2H, J=5.7Hz, CH₂ --OH); 2.27 (s, 3H, CH₃); 2.24 (s, 3H, CH₃); 2.00-1.60 (m, 4H,CH₂ CH₂). ¹³ C-NMR: 157.36; 137.45; 135.68; 126.92; 124.29; 110; 71.04;67.86; 62.68; 55.25; 34.10; 30.05; 25.52; 21.23; 21; 19.69.

1-(4-Methoxyphenyl)-pentane-1,4-diol (6k)

The acid 11k was reduced according to the general procedure and a yellowoil of 6k was obtained in 91% yield. ¹ H-NMR: 7.25 (d, 2H, Ar--H); 6.67(d, 2H, Ar--H); 4.6 (t, 1H, Ar--CH--OH); 3.80 (s, 3H, CH₃); 3.61 (t, 2H,CH₂ --OH); 2.1 (brs, 1H, OH); 1.9-1.2 (m, 7H, CH₂ OH).

General procedure for diols (12)

R²(1) Li (1.1-1.2 eq) was added to a solution of phtalid (1 eq) in THF(1-2 mL/mmol phtalid). The reaction mixture was stirred for 0.5-1 h at-78° C. and under N₂ -atmosphere followed by addition of R²(2) MgX (2.4eq) or LiAlH₄ to the dry ice-cooled reaction mixture. The cooling bathwas removed and the reaction mixture was stirred for indicated time atambient temperature followed by addition of aqueous NH₄ Cl (saturated).The aqueous layer was extracted with CH₂ Cl₂ and the combined organiclayers were washed with H₂ O, dried (MgSO₄) and concentrated to give thediol 12.

α-Phenyl-benzene dimethanol (12B)

Phtalid was reacted with PhLi (1 eq, 2M in cyklohexane/diethylether75/25) according to the general procedure. The reaction mixture was thentransferred to a slurry of LiAlH₄ in THF kept at 0° C. and under N₂-atmosphere. The temperature was raised to RT and the reaction mixturewas stirred for 1.5 hour. H2O was added very slowly at 0° C., followedby NaOH (15%) and H₂ O. CH₂ Cl₂ and MgSO₄ was added. The mixture wasfiltrated with a glass filter funnel and the filtrate was evaporated togive 74% of 12B. ¹ H-NMR: 7.65-7.15 (m, 9H, Ar--H); 5.99 (s, 1H,CH(Ph)--OH); 4.63 (s, 1H, OH); 4.63 (s, 1H, OH); 4.59 (d, 1H, J=12 Hz,CH₂ --OH); 4.42 (d, 1H, J=12 Hz, CH₂ --OH);

α -iso-Propylbenzene dimethanol (12C)

Isopropylmagnesiumchlorid (2.4 eg, 2M in diethylether) was added to asolution of phtalid (1 eg) in THF according to the general procedure.The reaction mixture was stirred for at ambient temperature for 5 h .Workup gave a mixture of α-isopropyl benzene dimethanol (12C) (74%) andα,α-diisopropyl benzene dimethanol (26%). The products were separated byflash chromatography (petroleumether/EtOAc 3/2). 12C was obtained in 61%yield. ¹ H-NMR: 7.45-7.2 (m, 4H, Ar--H); 4.69 (s, 2H, CH₂ --OH); 4.5 (d,1H, J=8 Hz, HO--CH--CH(CH₃)₂); 2.8 (brs, 2H, OH); 2.2-2 (m, 1H,CH(CH₃)₂); 1.11 (d, 3H, J=7 Hz, CH₃); 0.76 (d, 3H, J=7 Hz, CH₃). ¹³C-NMR: 141.81; 137.65; 129.02; 127.73; 127.26; 127.13; 76.60; 62.39;33.98; 19.34; 18.94.

α-Dimethylbenzene dimethanol (12D)

MeMgCl (2.4 eq, 2M in diethylether) was added to solution of phtalid (1eq) in THF according to the general procedure. After stirring for 3 h atRT and workup. 12D was isolated in 95% yield. ¹ H-NMR: 7.25-7.15 (m, 4H,Ar--H); 4.84 (s, 2H, CH₂ --OH); 1.69 (s, 6H, CH₃).¹³ C-NMR: 145.33;137.85; 131.66; 127.78; 127.02; 126.15; 74.35; 65.09; 32.20 (2C). IR:3270; 3083; 3068; 2988; 2974; 2963; 2945; 2880; 1484; 1452; 1437; 1380;1363; 1214; 1163; 1115; 1056; 1031; 1031; 937; 873; 763; 722.

α-Methyl-α-phenylbenzene dimethanol (12E)

Phtalid was reacted with McLi (1.1 eq, 1.6M in diethylether) for 1 h andthen with PhMgCl (2M in THF) according to the general procedure. Sirringfor 1.5 h at ambient temperature and workup gave acrude product in 80%yield which was purified by bulb-to-bulb destillation affording 12E in74% yield. ¹ H-NMR: 7.7-7.2 (m, 9H, Ar--H); 4.48 (t, 1H, J=5 Hz, OH);4.31 (dd, 1H. J=13 and 5 Hz, CH₂ --OH); 4.12 (dd, 1H, J=13 and 5 Hz, CH₂--OH); 2.86 (s, 1H, OH); 1.84 (s, 3H, CH₃). ¹³ C-NMR: 150.51; 146.62;141.00; 131.20; 128.26 (2C); 127.96; 127.57; 126.95; 126.71; 125.56;76.84; 63.71; 33.06.

α,α-Diphenylbenzene dimethanol (12F)

PhMgCl (2.5 eq, 2M in THF) was reacted with phtalid according to thegeneral procedure. Stirring for 3 h at ambient temperature and workupgave 2F in 94% yield. ¹ H-NMR: 7.6-7 (m, 13H, Ar--H); 6.66 (d, 1H, J=7Hz, Ar--H); 4.28 (s, 2H, CH₂ --OH). ¹³ C-NMR (CDCl₃ /DMSO): 146.69;146.53; 139.30; 131.87; 129.75; 127.56; 127.44; 127.39; 126.61; 126.60;82.37; 64.24. IR: 3430; 3255; 3058; 3034; 2966; 2894; 1597; 1488; 1447;1424; 1269; 1201; 1180; 1161; 1099; 1080; 1056; 1031; 1011; 1002; 955;931; 898; 765; 702; 640; 610.

α-Methyl-α-vinylbenzene dimethanol (12G)

Phtalid was reacted with MeLi (1.6M in diethylether) for 1 hour and thenwith vinylmagnesiumbromid (1M in THF) according to the generalprocedure. Stirring for 3.5 h at ambient temperature and workup gave acrude product in 95% yield. Purification by bulb-to-bulb destillationafforded 12G in 80% yield. ¹ H-NMR: 7.45-7.20 (m, 4H, Ar--H); 6.16 (dd,1H, J=11 and 17 Hz, CH═CH₂); 5.26 (d, 1H, J=17 Hz, trans in CH₂ ═CH);5.14 (d, 1H, J=11 Hz, cis in CH₂ ═CH); 4.93 (d, 1H, J=12 Hz, Ar--CH₂OH); 4.59 (d, 1H, J=12 Hz, Ar--CH₂ --OH); 1.74 (s, 3H, CH₃). ¹³ C-NMR:144.98; 143.83; 138.67; 131.85; 127.83; 127.62; 126.62; 112.14; 76.06;64.54; 29.65.

α-Phenyl-α -vinylbenzene dimethanol (12I)

Phtalid was reacted with PhLi for 2.5 h and then withvinylmagnesiumbromid according to the general procedure. Stirring for 3h at ambient temperature, workup, followed by bulb-to-bulb destillationgave 12I in 75% yield. ¹ H-NMR: 7.6-7.2 (m, 9H, Ar--H); 6.32 (dd, 1H,J=11 and 17 Hz, CH═CH₂); 5.3 (d, 1H, J=11 Hz, CH═CH₂); 5.14 (d, 1H, J=17Hz, CH═CH₂); 4.3 (AB, 2H, J=12 Hz, CH₂ --OH). ¹³ C-NMR: 145.38, 144.40;143.77; 138.84; 132.02; 128.57; 127.98; 127.82; 127.72; 127.51; 127.07;126.96; 126.85; 126.20; 114.05; 80.37; 64.25.

We claim:
 1. A process for the production of a 5-7 membered ring cyclic sulfonium salt compound comprising reacting a 1,4-, 1,5-, or 1,6-diol compound or a 5-7 membered ring cyclic ether compound with a mercapto compound and a strong protonic acid.
 2. Process according to claim 1, wherein the strong protonic acid is added to the mercapto compound and the resulting mixture is added to the diol or cyclic ether compound, or the strong protonic acid is added to a mixture containing the mercapto compound and the diol or cyclic ether compound, in substantially equimolar amounts with respect to the functional groups involved.
 3. Process according to claim 1, wherein the mercapto compound is a monofunctional mercaptan.
 4. Process according to claim 1, wherein the mercapto compound is a di- or polyfunctional mercaptan.
 5. A process according to claim 3 or 4, wherein the mercapto compound is selected fromi) a monofunctional mercaptan which is methyl mercaptan; a primary, secondary, or tertiary alkyl or cycloalkyl mercaptan; an aryl mercaptan, said aryl mercaptan being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, phenyl, phenoxy, or thiophenoxy; an arylalkyl mercaptan, said arylalkyl mercaptan being unsubstituted or mono- or independently polysubstituted by alkyl, alkoxy, or thioalkoxy; or ii) a di- or polyfunctional mercaptan of the general formula HS--[A--SH]_(m), wherein m≧1, and A independently represents alkylene, alkylenebisaryl, or aralkylene.
 6. Process according to claim 1, wherein the diol or cyclic ether compound is a monofunctional diol or cyclic ether compound.
 7. Process according to claim 1, wherein the diol or cyclic ether compound is a di- or polyfunctional diol or cyclic ether compound.
 8. A process according to claim 6 or 7, wherein the diol compound is selected fromj) a monofunctional diol which is a 1,4-, 1,5-, or 1,6-diol, which is i) unsubstituted; or ii) mono- or independently polysubstituted by alkyl, cycloalkyl, 1-alkenyl, aryl, said aryl being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, cyano, alkyl sulfonyl, aryl sulfonyl, aryl, aryloxy, or thioaryloxy; and/or iii) aryl fused, said aryl fused being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenyl, phenoxy, or thiophenoxy; or iv) cycloalkyl fused, which is unsubstituted or mono-or independently polysubstituted by alkyl or cycloalkyl; or jj) a di- or polyfunctional diol of the general formula C--[B--C]_(w), wherein w≧1, C independently represents a 1,4-, 1,5-, or 1,6-diol as defined above, and B independently represents alkylene, arylene, alkylenebisaryl or aralkylene.
 9. A process according to claim 6 or 7, wherein the 5, 6, or 7 membered ring cyclic ether compound is selected fromj) a monofunctional 5-7 membered ring cyclic ether selected from the group consisting of tetrahydrofuran, tetrahydropyran, or hexahydrooxepin, which cyclic ether is i) unsubstituted; or ii) mono- or independently polysubstituted by alkyl; cycloalkyl; vinyl; aryl, said aryl being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, cyano, alkyl sulfonyl, aryl sulfonyl, aryl, aryloxy, or thioaryloxy; and/or iii) aryl fused, said aryl fused being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenyl, phenoxy, or thiophenoxy; or iv) cycloalkyl fused, which is unsubstituted or mono- or independently polysubstituted by alkyl or cycloalkyl; or jj) a di- or polyfunctional cyclic ether of the general formula C--[B--C]_(w), wherein w≧1, C independently represents a tetrahydrofuran, a tetrahydropyran, or a hexahydrooxepin as defined above, and B independently represents alkylene, arylene, alkylenebisaryl, or aralkylene.
 10. Process according to claim 1, wherein the strong protonic acid is selected from hydrohalogenic, perhalogenic, tetrahaloboric, hexahaloantimonic, hexahaloarsenic, hexahalophosphoric, sulfonic, halogen-substituted alkyl or aryl sulfonic, phosphoric or sulfuric acid.
 11. Process according to claim 10, wherein the strong protonic acid is selected from such acids which produce a 5-7 membered ring cyclic sulfonium salt compound having a non-nucleophilic anion.
 12. Process according to claim 11, wherein the strong protonic acid is selected from perchloric, tetrafluoroboric, hexafluoroantimonic, hexafluoroarsenic, hexafluorophosphoric, p-toluensulfonic or triflic acid.
 13. A process according to claim 1, comprising reacting(a) a mercapto compound having the formula R¹ --SH, wherein R¹, in a monofunctional mercaptan, represents methyl; primary, secondary, or tertiary alkyl or cycloalkyl; aryl, said aryl being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, phenyl, phenoxy or thiophenoxy; arylalkyl, said arylalkyl being unsubstituted or mono- or independently polysubstituted by alkyl, alkoxy or thioalkoxy; or R¹, in a di- or a polyfunctional mercaptan, represents --[A--SH]_(m), wherein m≧1, and A independently represents alkylene, arylene, alkylenebisaryl, or aralkylene with (b) a diol compound selected from the group consisting of formula I: ##STR22## wherein n is 1,2, or 3,R² independently represents hydrogen, alkyl, cycloalkyl, or aryl; R³ independently represents hydrogen, alkyl, cycloalkyl, aryl, said aryl being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy; R⁴ independently represents hydrogen, alkyl, cycloalkyl, aryl, said aryl being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy; or R³ and R⁴ together form an aryl group fused with the corresponding carbon atoms of the carbon-carbon backbone chain; R⁵ independently represents hydrogen, alkyl, cycloalkyl, aryl, said aryl being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy; R⁶ independently represents hydrogen, alkyl, cyclkoalkyl, aryl, said aryl being unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy; or (c) a cyclic ether compound selected from the group consisting of formula II: ##STR23## wherein n, R², R³, R⁴, R⁵, and R⁶ are as defined above; and (d) a strong protonic acid having the formula HX, wherein X represents a halogen or a group of the formula MY_(r), wherein M represents Sb, P, B, As, or Cl; Y represents a halogen or oxygen; and r is an integer between 4 and 6, or X represents a group RSO₃ wherein R is OH, alkyl, aryl or halogen substituted aryl group, yielding a monofunctional cyclic sulfonium salt compound, when R¹ ≠--[A--SH]_(m), having the following structural formula III-1: ##STR24## wherein n, R¹, R², R³, R⁴, R⁵, R⁶, and X are as defined above with the exception of that R¹ ≠--[A--SH]_(m) ; or a di- or polyfunctional cyclic sulfonium salt compound, when R¹ =--[A--SH]_(m), having the following structural formula III-2: ##STR25## wherein n, m, A, R², R³, R⁴, R⁵, R⁶, and X are as defined above.
 14. Process according to claim 13, wherein R¹ and n are as defined in claim 13, one of R² =H and the other is aryl as defined in claim 13, R³ =H, R⁴ =H, R⁵ =H, R⁶ =H, and X represents SbF₆, PF₆, BF₄, ClO₄, or CF₃ SO₃.
 15. Process according to claim 13, wherein in the diol compound of I) or the cyclic ether compound of II), when n=1 and R³ and R⁴ together form a fused aryl group as defined, one R² can additionally define an 1-alkenyl, (R⁹)₂ C═C(R¹⁰)--, wherein R⁹ and R₁₀ independently represent hydrogen, alkyl, cycloalkyl, aryl, or a 5-7 membered ring formed by R⁹ and R¹⁰ ; yielding a cyclic sulfonium salt compound having the following structural formula IV: ##STR26## wherein R¹, R², R⁵, R⁶, R⁸, and X are as defined in claim 10, except that R¹ ≠--[A--SH]_(m).
 16. A process according to claim 5, wherein the monofunctional mercaptan is selected from the group consisting of: phenyl mercaptan, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, phenyl, phenoxy, or thiophenoxy, naphthylmercaptan and benzylmercaptan, which is unsubstituted or mono- or independently polysubstituted by alkyl, alkoxy, or thioalkoxy.
 17. A process according to claim 5, wherein the di- or polyfunctional mercaptan is a compound of the formula HS--[A--SH]_(m) wherein m is as defined above and A independently is selected from the group consisting of: C₂ -C₂₀ alkylene, phenylene, biphenylene, naphthylene, methylenebiphenyl and xylylene.
 18. A process according to claim 8, wherein the diol is selected from: j) a monofunctional diol that is ii) mono- or independently polysubstituted by vinyl, phenyl, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, cyano, alkyl sulfonyl, phenyl sulfonyl, phenyl, phenoxy or thiophenoxy; and/or iii) benzo fused which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, halogen, phenyl, phenoxy or thiophenoxy; or jj) a di- or polyfunctional diol of the formula C--[B--C]_(w), wherein w and C are as defined above, and B independently is selected from the group consisting of: C₂ -C₂₀ alkylene, phenylene, biphenylene, naphthylene, methylenebiphenyl and xylylene.
 19. A process according to claim 9, wherein the 5, 6 or 7 membered ring cyclic ether compound is selected from: j) a tetrahydrofuran, a tetrahydropyran, or a hexahydrooxepin, which is ii) mono- or independently polysubstituted by alkyl, cycloalkyl, vinyl, phenyl, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, cyano, alkyl sulfonyl, phenyl sulfonyl, phenyl, phenoxy or thiophenoxy; and/or iii) benzo fused which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, halogen, phenyl, phenoxy or thiophenoxy; or jj) a di- or polyfunctional diol of the formula C--[B--C]_(w), wherein w and C are as defined above, and B independently is selected from the group consisting of: C₂ -C₂₀ alkylene, phenylene, biphenylene, naphthylene, methylenebiphenyl and xylylene.
 20. A process according to claim 13, wherein R¹ in a monofunctional mercaptan is selected from the group consisting of phenyl, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, phenyl, phenoxy or thiophenoxy; naphthyl and benzyl which is unsubstituted or mono- or independently polysubstituted by alkyl, alkoxy or thioalkoxy; or R¹ in a di- or polyfunctional mercaptan represents --[A--SHS]_(m), wherein m is as defined above and A independently is selected from the group consisting of: C₂ -C₂₀ alkylene, phenylene, biphenylene, naphthylene, methylenebiphenyl and xylylene.
 21. A process according to claim 13, wherein in the diol compound of formula I:R² independently represents hydrogen, alkyl, cycloalkyl, or ##STR27## wherein y is an integer between 0 and 5, R⁷ independently represents alkyl, alkoxy, thioalkoxy, halogen, cyano, alkyl sulfonyl, phenyl sulfonyl and phenyl, phenoxy or thiophenoxy, each of which are unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy, thiophenoxy, cyano, alkyl sulfonyl, or phenyl sulfonyl; R³ independently represents hydrogen, alkyl, cycloalkyl, phenyl, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy; R⁴ independently represents hydrogen, alkyl, cycloalkyl, phenyl, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy; or R³ and R⁴ together form ##STR28## wherein z is an integer of between 0 and 4, and R⁸ independently represent alkyl, alkoxy, thioalkoxy, halogen or phenyl, R⁵ independently represents hydrogen, alkyl, cycloalkyl, or phenyl, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy, and R⁶ independently represents hydrogen, alkyl, cycloalkyl, or phenyl, which is unsubstituted or mono- or independently polysubstituted by alkyl, cycloalkyl, alkoxy, thioalkoxy, halogen, phenoxy or thiophenoxy.
 22. A process according to claim 15, wherein R⁹ and R¹⁰ independently represent hydrogen, alkyl, cycloalkyl, phenyl, or a 5-7 membered ring formed by R⁹ and R¹⁰.
 23. A process according to claim 15, wherein R² is a vinyl group. 